December 31, 2025

Parts of Southern Ontario To Ring In the New Year Buried in Up to 100cm of Additional Snow by Thursday

December 31, 2025/ Brennen Perry

***NOTE: YOU CAN CLICK ON THE MAP TO OPEN A ZOOMABLE IMAGE***

The weather story this week has been dominated by intense snow squalls that have practically paralyzed areas east of Lake Huron and southeast of Georgian Bay, and this prolonged event is far from finished.

As of Tuesday evening, many roads across Huron, Perth, Grey, Bruce and Simcoe Counties have been closed due to dangerous whiteout conditions and rapidly accumulating snow. Springwater Township has even issued an emergency alert asking residents to stay off the roads entirely, citing the inability for emergency services to safely respond.

Unfortunately, the situation is expected to continue into the New Year as snow squall activity remains locked in across the region. Additional road closures are possible as squalls continue to drift and redevelop through Grey and Bruce Counties on Wednesday. Blowing snow will remain a major concern, even during brief lulls in snowfall, keeping travel extremely hazardous.

With snow squalls persisting and slowly shifting over the next 48 hours, widespread snowfall totals east of Lake Huron are expected to range from 30 to 60cm by the end of Thursday. We continue to highlight a few high-impact pockets between Owen Sound and Goderich, including areas near Chatsworth, Wingham and Point Clark, where total snowfall could approach or even reach 100cm if the most intense bands remain locked in place.

Simcoe County will also continue to be affected on and off through Wednesday and Thursday. A narrow but intense zone that includes hard-hit Springwater Township, along with Wasaga Beach, Barrie and Angus, could pick up an additional 30 to 60cm of snow. Confidence is slightly lower here compared to Lake Huron, and some locations may underperform if the bands wobble, but significant impacts remain likely.

Late Wednesday into early Thursday morning, attention will also turn to Lake Ontario. A snow squall currently targeting upstate New York may drift northward into portions of Prince Edward County, including Picton. If this materializes, snowfall rates could quickly ramp up, leading to a fast 15 to 30cm of accumulation in just a few hours.

Snow squall activity is expected to continue into Friday, though the pattern begins to evolve. A more westerly flow later Thursday and Friday would favour the Bruce Peninsula, northern Simcoe County and Muskoka for continued lake effect snowfall.

**Hourly snowfall rates (cm)** - MAP FROM WEATHERBELL

Overnight, snow squall activity is expected to consolidate into two primary bands between Owen Sound and Goderich. Meanwhile, activity off Georgian Bay may briefly weaken overnight, although confidence in that outcome remains low. Radar trends continue to show a very robust squall set up between Orillia and Barrie, and even if it temporarily diminishes, it is expected to redevelop by mid-morning Wednesday.

The southern Lake Huron squall may also stretch farther inland at times, potentially reaching areas like Kitchener and parts of the western GTA, bringing brief but intense bursts of snow and rapidly changing road conditions.

These squalls are expected to persist through Wednesday morning and afternoon. By Wednesday evening, a weak Alberta clipper will move through Southern Ontario, briefly shifting winds and causing lake effect snow to become more scattered for a time.

That same clipper will also cause a wind shift over Lake Ontario, which could push an organized snow squall northward into Belleville, Picton and possibly Kingston. Snowfall rates in this band could reach 4 to 8cm per hour, with total accumulations of 15 to 30cm possible before the squall exits around midnight.

Snow squall activity should reorganize overnight into Thursday morning for regions east of Lake Huron and southeast of Georgian Bay as colder air deepens once again.

Based on the latest guidance, the strongest Lake Huron squall on Thursday looks most likely to set up somewhere near Kincardine, Wingham and Listowel, though this position could still shift. At the same time, the Georgian Bay squall is expected to continue hammering the Springwater and Barrie area.

By Thursday afternoon, the focus may shift northward as a multi-lake squall develops, stretching across the Bruce Peninsula, over Georgian Bay and into Midland and Orillia. Additional weaker bands may linger farther south across Huron and Perth Counties, including areas like Goderich and Stratford.

Looking ahead to Thursday night into Friday morning, the Georgian Bay squall may intensify further as winds become more westerly. This would allow the band to push northward into southern Muskoka, where it could lock in for much of the day Friday. A separate forecast focusing on Friday and the weekend will be issued closer to that time.

Before getting into final snowfall totals, it is important to remember that lake effect snow squalls are extremely localized. These narrow bands can produce massive snowfall in one community while areas just a few kilometres away receive very little. Forecast zones are intentionally broad to account for shifting winds and band placement, meaning not everyone within a zone will reach the listed totals.

With that in mind, there is strong model agreement on two primary zones with the highest snowfall potential ranging from 60 to 100cm, with localized amounts possibly exceeding 100cm if the most aggressive solutions verify.

The northern high-impact zone includes Owen Sound and Chatsworth, while the southern high-impact zone includes Point Clark and Wingham.

For the remainder of the eastern Lake Huron shoreline, snowfall totals of 30 to 60cm are expected, though isolated pockets could approach 75cm. Similar totals are possible from Wasaga Beach through Barrie, though totals there are more likely to remain on the lower end of the range.

Farther inland, areas including London, Woodstock, Kitchener, Fergus, Orillia, Innisfil, Keswick and Bradford could see 15 to 30cm. This is more conditional and depends on squalls stretching far enough inland in the right position.

That same 15 to 30cm potential also applies to parts of Prince Edward County, including Picton, where much of that snow could fall in a very short window Wednesday evening.

Surrounding regions extending southeast of London toward the Lake Erie shoreline, into Guelph, the north and eastern GTA, and along the Lake Ontario shoreline into Eastern Ontario could see 5 to 15cm by the end of Thursday. Most areas will likely stay closer to the lower end, though isolated pockets could approach 15cm due to intermittent lake effect bands.

The remainder of Southern Ontario, outside of northern Central and Eastern Ontario, can expect a general 2 to 5cm, mainly associated with the weak clipper system on Wednesday. Farther north, including the Ottawa Valley, less than 2cm is expected.

December 28, 2025

Powerful Wind Storm on Monday to Fuel Blizzard Conditions in Southern Ontario With Up to 25-50 cm of Snow Possible by Tuesday

December 28, 2025/ Brennen Perry

The major winter storm we have been focused on over the past few days has now arrived, bringing hazardous ice storm conditions to parts of Southern Ontario while Northern Ontario continues to deal with heavy snowfall. This system is already creating widespread travel issues and power concerns, and the worst impacts are still unfolding as we head into Monday.

Freezing rain will gradually come to an end by late morning or early afternoon on Monday for most areas as temperatures briefly climb above the freezing mark. While that may offer a short-lived improvement in conditions, it will be followed quickly by another round of dangerous weather as colder Arctic air surges back into the region from the west.

As this colder air pushes in, precipitation will rapidly transition from rain or freezing rain over to snow. This snow will become increasingly enhanced by Lake Huron and Georgian Bay, setting the stage for a prolonged and high-impact snow squall event across much of Southwestern and Central Ontario.

At the same time, a rapidly strengthening low-pressure system will track directly along the lower Great Lakes through early Monday. This setup will drive very strong winds across Southern and Northeastern Ontario, especially near the lakes, with widespread gusts exceeding 90 km/h and locally approaching or exceeding 100 km/h along exposed shorelines.

These powerful winds, when combined with heavy snowfall, will lead to blizzard conditions developing east of Lake Huron and southeast of Georgian Bay. Snow squalls will also intensify as the system pulls away, resulting in widespread snowfall totals of 25 to 50 cm across Grey-Bruce, Huron, Perth and Simcoe counties by the end of Tuesday.

The threat of blowing snow and sharply reduced visibility will not be limited to the traditional snowbelt regions. Localized blizzard conditions may extend across much of Southwestern and Central Ontario, including portions of the GTA. Even areas that do not receive significant snowfall could see near-zero visibility at times due to wind gusts in the 70 to 90 km/h range.

Given these conditions, road and highway closures are very likely in the hardest hit areas, especially across the snowbelt. Travel will be extremely hazardous and potentially impossible at times. Non-essential travel should be avoided through Monday and into Tuesday where possible.

Although winds are expected to gradually ease by early Tuesday, snow will continue to pile up east of Lake Huron and southeast of Georgian Bay. With very cold temperatures lingering through the remainder of the week, the snow squall risk could persist in some form for several additional days, depending on wind direction.

In the Ottawa Valley, freezing rain should come to an end by late morning on Monday as temperatures briefly rise above freezing. Meanwhile, colder air will already be invading areas closer to Lake Huron, with rain changing over to snow as early as mid-morning.

This transition will allow bands of heavy snow to develop through Southern and Central Ontario. There is also the potential for a frontal snow squall to form along the advancing cold front, producing a narrow but intense burst of snow that could rapidly deteriorate travel conditions.

**MAX WIND GUST (KM/H)** - MAP FROM WEATHERBELL

Adding to the severity of this setup will be the strong winds developing by mid-morning on Monday and continuing through the afternoon. Wind gusts of 90 to 100 km/h are possible near the shores of Lake Huron, Georgian Bay, Lake Ontario and Lake Erie, while areas farther inland could still see gusts reaching 70 to 90 km/h.

When these winds combine with intense snow squalls moving through late Monday morning, blizzard criteria will likely be met in several regions. This is especially true east of Lake Huron, including Huron, Perth, Grey and Bruce counties, as well as areas southeast of Georgian Bay near Lake Simcoe, where winds are expected to be strongest.

As the main system exits by Monday afternoon, snowfall will become increasingly driven by moisture from the lakes. This will concentrate the heaviest and most persistent snowfall within the snowbelt, particularly east of Lake Huron and around Lake Simcoe, where steady light to moderate lake effect snow will continue.

While snowfall rates during this phase may not be extreme, the combination of ongoing snow and strong winds will continue to produce near-zero visibility at times. Blizzard conditions may persist into the evening hours in the hardest hit regions despite somewhat lighter snowfall rates.

Winds will slowly begin to ease overnight into Tuesday morning, but blowing snow will remain a major issue. Gusts of 70 to 80 km/h may still occur east of Lake Huron early Tuesday, keeping travel conditions hazardous even as the most intense blizzard conditions begin to fade.

The peak period for blizzard conditions is expected from Monday morning through Monday afternoon. During this time, gusts near or above 90 km/h will combine with steady lake effect snow.

Blizzard criteria is most likely to be met around Lake Huron, including areas such as Tobermory, Wiarton, Owen Sound, Kincardine, Hanover, Goderich and Grand Bend, as well as across Simcoe County and parts of northern York and Durham regions.

What is a blizzard?

In Canada, blizzard conditions are officially defined as a combination of strong winds and blowing snow that severely reduces visibility.

Environment Canada considers blizzard criteria to be met when sustained winds or frequent gusts of at least 40 km/h combine with falling or blowing snow to reduce visibility to 400 metres or less. These conditions must persist for at least four consecutive hours to be classified as a blizzard.

It is important to note that blizzard conditions are based on visibility and wind, not snowfall amounts, meaning they can occur even with relatively light snowfall if winds are strong enough to cause widespread blowing and drifting snow.

Surrounding areas may also see periods of blizzard conditions, including London, Tillsonburg, Woodstock, Kitchener, Newmarket, Oshawa and Orillia. Confidence is slightly lower in these locations due to their distance from the core lake effect bands, but brief or localized blizzard conditions remain fairly likely.

Across Southwestern Ontario, including Windsor, Chatham and Sarnia, localized blizzard conditions are possible for a few hours Monday morning as heavier system snow moves through. Similar brief conditions could develop in the Niagara region and the outer Golden Horseshoe, where strong winds overlap with bursts of snow.

Overnight Monday into Tuesday morning, persistent snow squalls are expected to become established. One squall off Lake Huron may stretch through parts of Huron and Perth counties and at times reach into Woodstock and Brantford.

The Georgian Bay snow squall is expected to focus on the Collingwood to Barrie corridor and may occasionally extend into portions of York and Durham Region. These squalls may remain relatively locked in place through the night and morning hours, allowing snow to accumulate quickly as temperatures fall and accumulation efficiency increases.

By Tuesday afternoon, a shift in wind direction is expected to weaken the Georgian Bay squall. The Lake Huron squall will likely become dominant and gradually drift northward, stretching from Hanover through Kitchener and into the western GTA.

This northward drift is expected to continue into Tuesday evening, while a new squall may redevelop farther south, again focusing on Huron and Perth counties and extending toward Kitchener and Hamilton Tuesday night.

Although this forecast period ends Tuesday evening, snow squalls are expected to persist into Wednesday, with activity becoming more focused on Grey-Bruce. A separate forecast will be issued to cover conditions beyond Tuesday.

Given the meandering nature of the snow squalls east of Lake Huron, no single location is expected to dramatically outpace others in snowfall. Instead, widespread totals will be spread across communities such as Port Elgin, Chatsworth, Hanover, Flesherton, Kincardine, Mildmay, Minto, Point Clark, Wingham, Goderich, Listowel, Mitchell, Clinton, Exeter and Woodstock.

Snowfall totals in these areas are generally expected to range from 25 to 50 cm by the end of Tuesday. Similar totals of 25 to 50 cm are also likely for locations southeast of Georgian Bay, including Collingwood, Wasaga Beach, Barrie, Angus, Innisfil and Keswick.

Areas just outside the core lake effect zones, such as Grand Bend, London, Fergus, Arthur, Meaford, Owen Sound, Wiarton, Lion’s Head, Tobermory, Bradford and Orillia, are expected to see lower totals. These areas are generally looking at 15 to 25 cm of snow, though small shifts in wind direction could easily bring heavier snowfall into these communities.

For the remainder of Southwestern and Central Ontario, snowfall totals are expected to range from 5 to 15 cm. Most of this snow will fall early Monday with the system itself, followed by occasional lake effect snow through Tuesday.

Deep Southwestern Ontario, much of the GTA, the Niagara region and Eastern Ontario are expected to see less than 5 cm of snow overall. Despite lower accumulations, strong winds and brief bursts of snow could still lead to poor travel conditions at times.

December 28, 2025

Weathering the Storm: How to Prepare For an Ice Storm

December 28, 2025/ Alannah Campbell

In advance of the ice storm anticipated to impact the province, we at Instant Weather want to make sure that everyone is ready in the event of potential widespread and long term power outages. The impact of an ice storm is not just dependent on the amount of ice accretion, but also the winds associated with the storm. This is summarized using the Sperry-Piltz Ice Accumulation (SPIA) Index shown below.

It is important to be prepared for these situations so we have put together a list of items you should have on hand in case of an emergency:

Flashlight (windup or battery operated)
Radio (windup or battery operated)
Extra batteries
Portable cell phone charger
Water (2 litres per person per day)
Non-perishable canned or dried food
Manual can opener
Blankets
Candles and matches or lighters
First aid kit and any prescriptions/medical items
List of emergency numbers
Cash
Gasoline

Not sure what kind of food to have ready? Dried food like rice and pasta along with canned tuna can go a long way. Other items such as bread and granola bars are good for fibre and non-refrigerated fruits like bananas, oranges and apples help break up the high-sodium content found in dried foods. Another staple for many are storm chips. For water, an easy way to store a large amount is to fill a bathtub and use the water for drinking, cooking, and flushing toilets.

Since ice storms occur during the winter and early spring months, keeping warm is a major concern during extended power outages from ice storms. Electric baseboard heaters and space heaters will not work. However, natural gas furnaces will still work, but electrical components such as the blower, which forces the warm air through the vents, will not. There are some propane heaters that can be used indoors, but be careful because outdoor propane heaters produce carbon monoxide, making them very dangerous to use inside a home.

Another item worth adding to your emergency kit arsenal is a generator. Generators are available in a variety of sizes and capacities based on individual needs. There are a few things to consider when picking a generator: type, power and additional features.

There are home standby generators that are permanently in place and start up automatically when the power goes out. These units are large and can be quite expensive. There are also smaller, portable generators that either run strictly on gas or on either gas or propane (dual fuel). There is an added benefit of running your generator on propane as it less expensive to run.

Every generator has two power ratings: starting watts and running watts. In order to determine the power of generator you need, you first need to determine what appliances will be running. In the event of an emergency, you may find that the only necessities are the fridge and furnace fan.

It is EXTREMELY important to not run a generator in your house due to the risk of carbon monoxide poisoning.

With proper planning and preparation, everyone should be able to get through the stress that comes with extended periods without power. In the case of an ice storm, it’s important to stay indoors and reduce unnecessary travel. Also, we recommend not clogging up emergency lines with non-emergencies. Your power will be back before you know it!

December 27, 2025

End-of-Year Major Winter Storm to Bring Dangerous Ice Storm and Blizzard Conditions Across Southern and Northeastern Ontario Starting Sunday

December 27, 2025/ Brennen Perry

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As we close out 2025, the final few days are shaping up to be very messy and potentially dangerous. A complex and powerful winter storm is expected to impact Ontario between Sunday and Monday, bringing ice storm conditions to a wide swath of Central, Eastern and Northeastern Ontario.

With significant and prolonged freezing rain expected, widespread and long-lasting power outages are likely in the hardest hit areas. Ice accretion of up to 20mm is possible, and unfortunately, the regions most at risk include many of the same areas that were hit hard by last March’s major ice storm. In some locations, the power grid remains fragile, which raises additional concern.

Further north, the story will shift to heavy snow across much of Northeastern Ontario. Long-lasting blizzard conditions are possible here, with snowfall totals potentially exceeding 50cm by the time the storm finally winds down on Tuesday.

This system will also bring the risk of severe wind gusts across both Southern and Northern Ontario on Monday. Areas closest to the shorelines of the Great Lakes will be at the greatest risk, with damaging wind gusts in excess of 90 km/h possible. There may even be some isolated pockets, mainly in the Niagara region, that approach 100 km/h.

Southwestern Ontario will be largely unaffected by the first phase of the storm. Temperatures here will rise steadily on Sunday, peaking in the double digits by late afternoon or evening. Rain will fall steadily through Sunday and into early Monday. However, conditions will change rapidly as temperatures plunge Monday morning, creating a potential flash freeze as all that rainfall quickly freezes on roads and other surfaces.

Later on Monday, strong wind gusts will combine with steady, moderate snowfall around Lake Huron and Georgian Bay. Blizzard conditions could develop during the afternoon and evening as visibility drops and blowing snow becomes intense.

The storm will begin to take shape late Sunday morning as the first bands of precipitation spread into Northeastern Ontario and parts of Southwestern Ontario. This will initially include some light freezing rain extending from London through Kitchener and Barrie.

Sunday afternoon will be heavily dependent on the position of the freezing line, which is expected to slowly expand northeastward. Areas to the southwest will gradually climb above freezing and escape the worst of the icing, while regions farther northeast remain locked below zero.

By around midday, most of Central and Eastern Ontario is expected to remain well below freezing. Higher elevation areas northwest of the GTA will hover close to the freezing mark, including Hamilton, Kitchener, Guelph and Orangeville. How long the cold air remains trapped at the surface will play a major role in how impactful the icing becomes in places like the Kitchener area.

Meanwhile, Deep Southwestern Ontario, including Windsor, will already be sitting in the mid single digits. Heavy rain will be ongoing here, but there will be no winter storm impacts during the day on Sunday.

As Sunday afternoon progresses, the freezing rain shield will expand northward into the North Bay area and the Ottawa Valley. The heaviest icing during this time is expected to focus around Lake Simcoe.

Locations such as Bracebridge, Lindsay, Orillia, Peterborough, Barrie, York Region, Kitchener and Orangeville appear likely to see the worst icing on Sunday afternoon. Precipitation rates will be quite heavy, allowing ice to accumulate rapidly on roads, trees and power lines.

At the same time, Southwestern Ontario, including the Niagara region, will see heavy rain, with some embedded non-severe thunderstorms possible. Rainfall totals could be significant, with some localized areas exceeding 50mm by Monday morning.

Flooding could be a concern as frozen ground has a lower ability to absorb the rain.

As we move into Sunday evening, the freezing rain zone will become very expansive as the system rapidly intensifies. Intense icing is expected from Sault Ste. Marie through Sudbury and North Bay and into Central and Eastern Ontario.

Meanwhile, colder and more entrenched air across Northeastern Ontario will allow precipitation to switch over to heavy snow. Areas from Wawa to Kapuskasing will see snowfall rates increase significantly.

By late Sunday evening, uncertainty will increase across southern portions of Central and Eastern Ontario as temperatures hover very close to the freezing mark. This includes Barrie, Orillia, Muskoka, the Kawarthas, Peterborough and Kingston. If cold air proves even slightly more resilient than currently expected, these regions could remain below freezing overnight and continue to experience ice storm conditions.

In Deep Southwestern Ontario, it will feel almost surreal for late December, with temperatures climbing into the double digits even around midnight.

Overnight Sunday into early Monday, heavy snowfall will expand farther south across Northeastern Ontario as colder air continues to advance. Areas including Sault Ste. Marie, Timmins and the Cochrane corridor are expected to transition from freezing rain to heavy snow.

This transition is especially concerning for the power grid, as heavy snow may accumulate on top of ice-coated trees and power lines. That combination could lead to significant damage, particularly in more remote and heavily forested areas.

For the Sudbury to Ottawa Valley corridor, freezing rain is expected to continue through the overnight hours with ice accumulation steadily increasing. This region is likely to see some of the worst overall impacts due to the length of time spent under freezing rain.

By late Monday morning, the next phase of the storm will unfold in the form of a flash freeze across Deep Southwestern Ontario. Rapidly falling temperatures will cause any remaining moisture to freeze quickly on untreated surfaces, creating extremely hazardous travel conditions.

As freezing rain ends across Central and Eastern Ontario and temperatures drop by Monday afternoon, the true extent of the damage will become clear. Current data suggests the hardest hit areas may include Kawartha Lakes, Peterborough, Haliburton, Bancroft, Tweed, Kaladar, Renfrew, Perth and Ottawa. Ice accretion in these regions may range from 15 to 20mm, with localized pockets potentially approaching 25mm.

In the Ottawa Valley, temperatures may not rise above freezing at all before the flash freeze arrives. This would lock ice in place for an extended period, worsening impacts. Farther south, a brief window above freezing may help slightly reduce overall damage.

A broader area of Central and Eastern Ontario, along with higher elevations northwest of the GTA and parts of Northeastern Ontario, can expect between 10 and 15mm of ice. This includes Brockville, Kitchener, Guelph, Newmarket, Barrie, Muskoka, Parry Sound, North Bay, Sudbury and Sault Ste. Marie.

Ice amounts will decrease closer to Lake Ontario and away from higher terrain. Between 5 and 10mm is possible from Kingston through the northern GTA and higher elevations around Hamilton and Grimsby. Less than 5mm is expected for Oshawa, Mississauga, Hamilton and Meaford. Little to no icing is expected near Lake Huron and Lake Ontario, where temperatures remain above freezing for most of the event.

While freezing rain will end, hazardous conditions will continue. By late Monday morning, rain will change to heavy snow around Lake Huron and Georgian Bay. Strengthening winds of 70 to 90 km/h will create dangerous travel conditions and likely meet blizzard criteria.

Combined with the flash freeze, widespread road closures are likely east of Lake Huron and into Northeastern Ontario. Travel should be avoided in these regions.

The strongest wind gusts are expected during the morning and afternoon on Monday before slowly easing in the evening. Areas exposed to the lakes will see the worst winds, with gusts of 95 to 110 km/h possible across the Niagara region and into Prince Edward County.

Near damaging gusts of 85 to 95 km/h are possible along the Lake Ontario shoreline from Kingston through the GTA and Hamilton, as well as along the Lake Erie and Lake Huron shorelines and southeast of Georgian Bay into Simcoe County and Orangeville.

Elsewhere across Southwestern Ontario and southern portions of Central and Eastern Ontario, peak gusts of 75 to 85 km/h are expected. Farther north, including the Ottawa Valley, gusts will generally range from 65 to 75 km/h. While lower, these winds may cause greater damage due to occurring after significant ice accumulation.

Conditions will remain treacherous through Monday afternoon with strong winds and persistent snowfall, especially near the lakes, where blizzard conditions continue.

Snowfall totals associated with the main system will wrap up by Tuesday morning. Central Ontario and parts of Southwestern Ontario east of Lake Huron can expect 5 to 15cm of snow, with localized totals exceeding 15cm near Kincardine, Hanover and Owen Sound due to lake enhancement.

Elsewhere across Southern Ontario, snowfall amounts will generally range from 2 to 5cm.

In Northern Ontario, snowfall totals will be far more significant. The highest amounts are expected in Cochrane, Timmins, Chapleau and Kirkland Lake, where totals of 50 to 75cm are possible between Sunday evening and Tuesday morning.

A broader swath of Northeastern Ontario, including Wawa and Temiskaming Shores, may see 30 to 50cm. Areas such as Elliot Lake, Sault Ste. Marie and Kapuskasing could receive 20 to 30cm, while North Bay, Sudbury and Manitoulin Island are expected to pick up between 10 and 20cm.

December 27, 2025

BREAKING: Major Winter Storm Expected for Ontario Beginning Sunday with Blizzard Conditions, Up to 50cm of Snow, 70-100km/h Winds, Flash Freezing, and 10-20mm of Freezing Rain

December 27, 2025/ Adam Skinner

ZOOMED VERSION OF MONDAY FORECAST TO SHOW MORE LOCATIONS IN SOUTHERN ONTARIO - NOTE: CLICK OR TAP THE IMAGE TO OPEN AN IMAGE YOU CAN ZOOM

Environment Canada has upgraded their forecast map for this major winter storm expected to affect Ontario late Sunday through Monday. In their forecast, they’re mentioning a high risk for blizzard conditions, 70-100km/h wind gusts, 15-50cm of snow, intense snow squalls, 10-20mm of freezing rain and a flash freeze for parts of northeastern and southern Ontario.

NOTE: CLICK OR TAP THE IMAGE TO OPEN AN IMAGE YOU CAN ZOOM

Sunday, December 28th:

The storm begins on Sunday for many and really begins to ramp up Sunday evening and overnight. Below is Environment Canada’s location specific details:

”Location A: Portions of northeastern, eastern and central Ontario. Parts of the Greater Golden Horseshoe.

Hazard(s): Ice

Timing: Afternoon and evening into Monday.

Impact(s): Icy surfaces such as roads and walkways.

Impact level: High (3/4)
Confidence level: Moderate (2/4)

A long-duration freezing rain event is expected to begin in the afternoon, and evening for eastern Ontario. The event remains uncertain in terms of the areas that will receive the highest amount of freezing rain. Confidence is highest over areas of higher terrain and central Ontario.

———

Location B: Parts of southwestern Ontario and the Golden Horseshoe.

Hazard(s): Ice, Rain

Timing: Afternoon through evening.

Impact(s): Possible difficult travel conditions. Flooding in low-lying areas including roads.

Impact level: Low (1/4)
Confidence level: Moderate (2/4)

Freezing rain is possible with the approach of a low pressure system. Freezing rain is expected to be brief for most areas before a transition to rain, where up to 40 mm is possible through Monday morning.

———

Location C: Parts of northeastern Ontario.

Hazard(s): Ice

Timing: Early morning.

Impact(s): Possible difficult travel conditions.

Impact level: Moderate (2/4)
Confidence level: Low (1/4)

Patchy areas of freezing rain and ice pellets are possible.

———

Location D: Parts of southwestern Ontario and the Niagara Peninsula.

Hazard(s): Rain, Thunderstorm

Timing: Morning through Monday.

Impact(s): Flash flooding and water pooling on roads.

Impact level: Low (1/4)
Confidence level: Moderate (2/4)

Rainfall ahead of a low pressure system could bring amounts of 20 to 40 mm. Thunderstorms are also possible in the evening into Monday morning. Locally higher rainfall totals up to 50 mm are possible under heavier showers or thunderstorms.

———

Location E: Parts of northeastern Ontario.

Hazard(s): Ice

Timing: Late afternoon or evening into Monday.

Impact(s): Possible difficult travel conditions.

Impact level: Moderate (2/4)
Confidence level: Low (1/4)

Freezing rain is possible with the approach of a low pressure system. Ice pellets are likely to mix in as well.”

ZOOMED VERSION OF SUNDAY FORECAST TO SHOW MORE LOCATIONS IN SOUTHERN ONTARIO - NOTE: CLICK OR TAP THE IMAGE TO OPEN AN IMAGE YOU CAN ZOOM

Monday, December 29th:

Here’s Environment Canada’s details for Monday:

”Location A: Eastern and central Ontario.

Hazard(s): Ice, Rain, Wind

Timing: Ending in the morning or early afternoon.

Impact(s): Icy surfaces such as roads and walkways. Broken tree branches from ice build-up. Utility outages.

Impact level: High (3/4)
Confidence level: High (3/4)

A strong and deep low will track across the area. A significant, prolonged freezing rain event is expected to continue into the morning or early afternoon. Lesser ice accretion is expected for areas just east of Georgian Bay and north of Lake Ontario. Wind gusts up to 60 km/h in the wake of the system may be impactful to areas with ice build-up. After temperatures rise above zero, up to 20 mm of rain is also possible.

———

Location B: Portions of northeastern and central Ontario.

Hazard(s): Snow, Blowing snow, Ice

Timing: Beginning in the morning.

Impact(s): Difficult travel conditions, reduced visibility and possible road closures. Icy surfaces such as roads and walkways.

Impact level: High (3/4)
Confidence level: Low (1/4)

With a deep low moving across the region, snowfall of 10 to 20 cm and blowing snow are possible. Ice pellets are likely to mix in for much of the region, reducing total snowfall accumulations. Freezing rain is also possible for regions south of Sudbury including Manitoulin Island.

———

Locations C: Southeast of Georgian Bay, and northeastern shores of Lake Ontario and Lake Erie.

Hazard(s): Wind, Blowing snow, Snow, Ice

Timing: Beginning in the morning.

Impact(s): Loose objects may be tossed. Possible power outages. Difficult travel conditions, reduced visibility and possible road closures.

Impact level: Moderate (2/4)
Confidence level: High (3/4)

Strong westerly or northwesterly wind gusts of up to 100 km/h are possible in the wake of the strong low pressure system. Brief bands of heavy snow and local blowing snow are likely to accompany the strong winds by Monday afternoon. Snow squalls are expected to develop off of Georgian Bay in the evening and continue through Tuesday. Icy surfaces are also possible with temperatures quickly falling to below zero in the morning.

———

Locations D: Portions of northeastern Ontario from Chapleau to Timmins.

Hazard(s): Snow, Blowing snow

Timing: Beginning early morning.

Impact(s): Hazardous travel conditions, reduced visibility and road closures. Snow covered and slippery surfaces such as roads and walkways.

Impact level: High (3/4)
Confidence level: High (3/4)

With a deep low moving across the region, heavy snowfall up to 50 cm and blowing snow are possible, with local blizzard conditions possible especially for regions closer to Lake Superior. Travel on Highway 11 will likely be disrupted. The snow is expected to gradually taper to flurries Monday overnight or Tuesday morning, while the moderate to strong winds and local blowing snow are expected to continue through Tuesday afternoon.

———

Location E: Portions of northeastern Ontario east of Lake Superior.

Hazard(s): Snow, Wind, Blowing snow

Timing: Beginning early morning.

Impact(s): Possible power outages. Dangerous travel conditions, reduced visibility and road closures. Snow covered and slippery surfaces such as roads and walkways.

Impact level: High (3/4)
Confidence level: High (3/4)

With a deep low moving across the region, heavy snowfall up to 40 cm and blizzard conditions are possible with strong wind gusts of up to 90 km/h. Travel on highway 17 will likely be disrupted. The snow is expected to gradually taper Monday evening while the strong winds and blowing snow conditions are expected to improve later Monday night.

———

Locations F: Portions of northeastern Ontario from Marathon to Little Abitibi

Hazard(s): Snow, Blowing snow

Timing: Beginning Sunday night.

Impact(s): Difficult travel conditions, reduced visibility and possible road closures. Snow covered and slippery surfaces such as roads and walkways.

Impact level: Moderate (2/4)
Confidence level: High (3/4)

Heavy snowfall up to 15 cm and local blowing snow are possible. Conditions are expected to be the poorest near Lake Superior.

———

Location G: Southeast of Lake Huron.

Hazard(s): Wind, Blowing snow, Snow, Ice

Timing: Beginning in the morning.

Impact(s): Dangerous travel conditions, reduced visibility and road closures. Possible power outages. Icy surfaces such as roads and walkways.

Impact level: Extreme (4/4)
Confidence level: High (3/4)

Blizzard conditions in snow squalls are possible with strong wind gusts of up to 100 km/h in the wake of the strong low pressure system. Near zero visibility and bursts of heavy snow are likely especially in the afternoon. Icy surfaces are also possible with temperatures quickly falling to below zero early in the morning.

———

Location H: Portions of southwestern and central Ontario, as well as the Golden Horseshoe.

Hazard(s): Ice, Wind, Blowing snow

Timing: Beginning in the morning.

Impact(s): Loose objects may be tossed. Possible reduced visibility. Icy surfaces such as roads and walkways.

Impact level: Moderate (2/4)
Confidence level: Moderate (2/4)

Icy surfaces are possible with temperatures quickly falling to below zero in the morning. Strong wind gusts up to 70 km/h are possible through the day. Local blowing snow may accompany these wind gusts, especially over southwestern Ontario.”

Tuesday, December 30th:

And, of course, no winter storm would be complete without snow squalls the next day. Environment Canada expecting snow squalls for London, Goderich, Barrie, Newmarket, Collingwood, Wasaga Beach, Stayner, Angus and surrounding communities on Tuesday. 10-20cm possible with gusty winds creating blowing snow and possible whiteouts. Specifically in the squalls east of Lake Huron, 70km/h wind gusts are possible as per Environment Canada:

”Locations A and B: Areas southeast of Lake Huron and Georgian Bay.

Hazard(s): Snow, Blowing snow, Wind.

Timing: Tuesday.

Impact(s): Difficult travel conditions, reduced visibility and possible road closures.

Impact level: High (3/4)
Confidence level: Moderate (2/4)

In the wake of the low pressure system, snow squalls are likely to set up off Lake Huron and Georgian Bay with snowfall up to 20 cm, local blowing snow, and strong wind gusts of up to 70 km/h.”

In summary:

It’s looking likely at this point that Sunday into Monday will be a major winter storm with significant impacts to travel, power outages, icy conditions, significant snowfall, whiteouts, and intense, potentially damaging wind gusts. If you don’t have to travel during this storm, that would be best. However, if it’s an emergency or you’re on the front lines, please give yourself as much time as possible. More details ASAP.

December 26, 2025

Boxing Day Winter Storm Poised to Deliver Ice Storm Risk and Heavy Snow to Southern Ontario on Friday

December 26, 2025/ Brennen Perry

With Christmas now behind us, the focus turns to the final stretch of 2025 as we approach New Year’s next Thursday. And it’s looking like the last seven days of the year will be anything but quiet when it comes to the weather across Southern Ontario.

That active pattern becomes clear very quickly with a looming Boxing Day winter storm expected to bring a messy mix of precipitation. Some areas will see periods of heavy snowfall, while others could be dealing with a potentially damaging ice storm with prolonged freezing rain through much of the day.

For much of Central Ontario, along with parts of the Golden Horseshoe and into portions of Southeastern Ontario, the primary concern will be snowfall. Widespread totals in the 10 to 20 cm range are possible by the end of Friday. The Ottawa Valley is expected to remain on the lower end, generally staying under the 10 cm mark.

The forecast becomes more complicated through Southwestern Ontario, extending through Hamilton and into the Niagara Region. Here, a mix of snow and ice pellets is expected, which will limit snowfall totals but still create hazardous travel conditions.

The freezing rain risk has shifted slightly northward in the latest model guidance, as warmer air aloft is now expected to push deeper into Southern Ontario than earlier projections suggested. This places the Sarnia to London corridor in the bullseye for the highest ice accretion. Freezing rain totals of 10 to 15 mm are possible, which could result in significant power outages and very icy road conditions.

Beyond Friday, attention is already turning to another slow-moving system expected to arrive Sunday and linger into Monday. This system appears to have access to much more moisture compared to Friday’s storm, raising the concern for a prolonged period of freezing rain that could last anywhere from 12 to 24 hours.

What adds to the concern is that current model guidance is focusing this next threat over parts of Central and Eastern Ontario, the same areas that were hardest hit by last winter’s major ice storm. There is still uncertainty with the exact track, and it could shift north or south, but it is something we are watching very closely.

Before we get ahead of ourselves, the immediate focus remains on Friday’s storm. Precipitation is expected to begin during the early to mid-morning hours as bands move in from the west. Light to moderate snow will spread into Grey-Bruce, Simcoe County, Muskoka and the GTA during this time.

For Windsor, Chatham and Sarnia, light freezing rain is expected to begin by mid-morning. Precipitation may be somewhat scattered at first but will steadily increase in coverage and intensity as the morning progresses.

By late morning, the worst conditions should be underway, with heavy icing ongoing around Chatham, Sarnia and London. Travel conditions in these areas are expected to deteriorate quickly.

Further north and east, heavy snow will be the main concern across Muskoka, Simcoe County, Peterborough and the eastern GTA, including the City of Toronto.

Between the freezing rain to the southwest and the heavy snow to the north and east, a corridor of ice pellets is expected to develop from the Lake Huron shoreline through Kitchener and into Hamilton.

Poor conditions will persist into Friday afternoon, with steady snowfall continuing across Central Ontario into Kingston. Wind gusts approaching 40 km/h may lead to localized blowing snow, further reducing visibility at times.

The ice pellet zone may also push further into the GTA, with Toronto potentially switching over to ice pellets for a time. This would limit snowfall totals and keep them closer to the 10 cm range.

Sarnia and London are expected to remain locked into freezing rain through much of the afternoon. There may be some hope for the Chatham area, where temperatures could briefly rise just above freezing and allow a changeover to rain by mid-afternoon. However, this is right on the line and could still go either way. Windsor and Leamington are expected to remain solidly in the rain zone.

The system is expected to gradually wind down later Friday afternoon and into the early evening. Precipitation will taper off first across western areas, then slowly come to an end across the Golden Horseshoe and Eastern Ontario by late evening.

Based on the latest data, the highest ice storm concern has been focused on the Sarnia, Lambton, Middlesex and London corridor. While there is still some disagreement on exact intensity, the potential exists for ice accretion exceeding 10 mm, with localized amounts approaching 15 mm.

Communities included in this higher risk zone include Wallaceburg, Sarnia, Petrolia, Thamesville, Lambton Shores, Grand Bend, St. Thomas and London.

Across Essex County, the highest ice accretion is expected in the northern portions of the county, including Windsor and Tilbury. These areas could see 5 to 10 mm of ice before a changeover to rain. Closer to the Lake Erie shoreline, including Leamington, icing should be minimal, generally under 2 mm, as temperatures rise above freezing more quickly.

Further north, freezing rain amounts will be reduced as ice pellets dominate initially, with freezing rain gradually mixing in later. Locations such as Lucan, Exeter, Woodstock, Tillsonburg, Simcoe, Port Colborne and Fort Erie could see a faster transition to freezing rain, with 5 to 10 mm of ice possible following a few hours of ice pellets.

For Huron and Perth counties, including Kitchener, Brantford and Niagara Falls, ice pellets are expected to linger longer. This will limit freezing rain to only a few hours near the end of the storm, with ice accretion generally in the 2 to 5 mm range. Less than 2 mm of icing is expected for Hamilton, Guelph and southern Grey-Bruce.

On the snowfall side of the storm, the highest totals are expected to range from 10 to 20 cm across Northeastern Ontario, down into Central Ontario and parts of Eastern Ontario.

This includes areas such as Sudbury, North Bay, Parry Sound, Muskoka, Simcoe County, York Region, Toronto, Durham Region, the Kawarthas, Peterborough and Kingston.

Lower snowfall totals are expected in the Ottawa Valley, where amounts of 2 to 5 cm are forecast for Ottawa and 5 to 10 cm from Bancroft into Brockville. This is due to the core of the system’s moisture remaining further south.

South of the heaviest snow band, totals will decrease as ice pellets mix in later in the storm. Grey-Bruce, Orangeville, Guelph and the western GTA are currently expected to see 5 to 10 cm, though some model solutions suggest even less if mixing becomes more dominant.

Even lower snowfall totals are expected east of Lake Huron into Hamilton and Niagara, where less than 5 cm is forecast as ice pellets and freezing rain become the primary precipitation types.

Once this system exits Friday night, Saturday should bring a brief period of calmer weather. However, that break will be short-lived, as another potentially high-impact winter storm is expected to approach as early as Sunday, possibly arriving in multiple waves.

The overall setup supports the potential for a prolonged area of freezing rain that could remain locked in place into Monday. This raises concern for a significant ice storm event, potentially similar in nature to last winter’s devastating storm across Central and Eastern Ontario.

Those same regions are once again in the early bullseye. While there is still time for this forecast to change, this is the type of setup where residents should begin thinking ahead and preparing for the possibility of extended power outages if the scenario does not improve.

We will continue to monitor this closely and will have a more detailed update once we get through Friday’s storm.

December 25, 2025

BREAKING: Environment Canada Forecasting Possible Significant Freezing Rain for Parts of Ontario

December 25, 2025/ Adam Skinner

Environment Canada is monitoring a deep low-pressure system expected to affect Ontario late Sunday through Monday. While details remain uncertain this early on, a “significant, prolonged period of freezing rain event” is possible as per Environment Canada’s meteorologists. In addition to the freezing rain, heavy snow, and strong winds are possible in parts of the province. Surfaces like roads, sidewalks, and trees may become dangerously icy, and widespread power outages are possible if this continues to trend strong.

Sunday, December 28th:

Location A (Ice, 3mm): A potential freezing rain event could glaze roads and walkways across eastern and central Ontario and parts of the Greater Golden Horseshoe. Confidence remains low regarding exact timing, precipitation type, and coverage.

Location B (Snow, 5–10cm): Northeastern Ontario may see 5 to 10 cm of snow, leading to difficult travel conditions and reduced visibility. Snowfall amounts and affected areas remain uncertain this early on.

Monday, December 29th:

Location A (Ice, 10mm+): A strong and deep low could produce significant, prolonged freezing rain across eastern and central Ontario, with ice accretion on trees and power lines leading to branch breakage and power outages.

Location B (Snow & Blowing Snow, 15–20 cm): Portions of northeastern and central Ontario may receive 15–20 cm of snow with blowing snow and gusts up to 70 km/h, causing difficult travel and reduced visibility.

Locations C & D (Wind, 70–90 km/h): Westerly or northwesterly wind gusts of 70–90 km/h are possible along the eastern shores of Lake Huron, northeastern shores of Lake Ontario, and Lake Erie, potentially tossing loose objects and causing power outages.

Location E (Ice & Wind, 10 mm & 80 km/h): Southeast of Georgian Bay may experience a combination of prolonged freezing rain and wind gusts up to 80–90 km/h, resulting in ice build-up and possible significant impacts. Confidence remains moderate to low for precipitation type, amounts, and exact areas but we’ll continue to monitor this carefully over the next few days to see how it progresses.

In summary:

The exact details of this event continue to unfold and there is potential for this to change. However, there is quite a bit of agreement on the models at this time regarding the prolonged freezing event with strong wind gusts. Please be prepared for slippery roads, reduced visibility and potential power outages and now would be a good time to begin reviewing your travel plans if you plan to travel on Sunday or Monday. More details ASAP.

December 24, 2025

Potential Boxing Day Winter Storm Targets Southern Ontario With Significant Freezing Rain Risk and Up to 15-20cm of Snow

December 24, 2025/ Brennen Perry

While winter weather has mostly taken a breather across Southern Ontario over the past week, things are about to turn active again as we head into the final days of 2025.

That change begins on Boxing Day with a messy winter system expected to slide through Southern Ontario. This system will bring a wide range of hazards, including the threat of significant freezing rain in Deep Southwestern Ontario and more widespread snowfall across much of the rest of the region.

There are still some question marks surrounding this storm, particularly when it comes to how strong it ultimately becomes. Some lower-resolution models show a fairly robust system with plenty of moisture to work with. At the same time, higher resolution guidance that is now coming into range is hinting at some drier pockets, which could cause this system to underperform in spots.

Complicating matters further is the fact that this system has the characteristics of an Alberta Clipper. Clippers are notorious for being difficult to forecast since they often lack a deep source of moisture, and small changes can make a big difference in precipitation type and totals.

What we do know at this point is that impacts will vary significantly across Southern Ontario. The highest risk area continues to be Deep Southwestern Ontario, especially the Windsor, Chatham and Sarnia region, which currently sits in the bullseye for prolonged freezing rain.

In these areas, sustained freezing rain could lead to substantial ice accretion on roads, trees and power lines. This would result in dangerous travel conditions and an increased risk of power outages. With over 10mm of icing possible, there is also concern for widespread tree damage as branches struggle under the weight of the ice.

Further north, from areas east of Lake Huron through the Greater Toronto Area and into Central and Eastern Ontario, the primary precipitation type is expected to be snow. Snow will fall steadily through much of the day on Friday with general accumulations of 5 to 15cm by the end of the day. Locally higher amounts approaching 20cm are possible west of Lake Ontario around the Toronto area due to lake enhancement.

The first bands of precipitation are expected to arrive early to mid-morning on Friday, spreading across Lake Huron into Southwestern Ontario. As the system moves in, it will encounter a stubborn layer of cold air near the surface across Deep Southwestern Ontario, including Windsor, Leamington, Chatham and Sarnia.

At the same time, warmer air will surge in above the surface, creating a classic setup for freezing rain. This warm layer aloft melts the snow into rain, which then freezes on contact with cold surfaces at the ground.

**850MB TEMPS (1.5KM ABOVE GROUND)** - MAP FROM WEATHERBELL

The biggest challenge with events like this is determining how far north and how deep that warm layer extends. This is the key factor that decides whether precipitation falls as ice pellets or as freezing rain.

Temperatures roughly 1.5km above the surface vary considerably between models. The Canadian model is more aggressive, pushing the warm layer farther north into Southwestern Ontario and even as far as London.

Overall, model consensus places the freezing line somewhere near a Sarnia to London corridor. Areas south of this line are more likely to see freezing rain, while areas to the north will see a mix of ice pellets and snow.

By the early afternoon, heavier snow will begin spreading into Central Ontario and the Golden Horseshoe as precipitation from Northern Ontario moves southeast across Georgian Bay. At the same time, freezing rain will be ongoing around Windsor, Chatham and Sarnia.

There are indications that temperatures may slowly climb above freezing for southern Essex County, including Leamington and eventually Windsor. There is still disagreement on the exact timing of this changeover, but it appears most likely sometime during the early to mid-afternoon.

If temperatures do rise above freezing, freezing rain would switch to plain rain, and any ice accretion would begin to melt. How quickly this happens will be critical in determining overall impacts. If the warmup is delayed until later in the day or temperatures stubbornly remain below freezing before dropping Friday night again, impacts could be significantly worse.

For areas like Chatham-Kent, Sarnia and St. Thomas, there is growing concern that temperatures may remain below freezing for much of the event. This would allow ice to accumulate for a prolonged period, with over 10mm of accretion possible. Ice amounts of this magnitude are capable of bringing down tree limbs and power lines, potentially leading to power outages that could last for several days.

By mid-afternoon, the heaviest snow will be pushing through the Golden Horseshoe. Some models are showing the potential for lake enhancement along the Lake Ontario shoreline from Niagara through Hamilton and into Toronto. If this develops, snowfall rates could briefly spike to 3 to 5cm per hour compared to the more general 1 to 2cm per hour elsewhere.

It is also important to note that ice pellets may mix in at times, which can limit snowfall totals since ice pellets are denser than snow. This is most likely for areas such as London, Kitchener, Hamilton and Niagara, where conditions are more supportive of mixed precipitation. Areas closer to Toronto and farther north into Central Ontario should see more consistent snow.

Light to moderate snow will also spread into Eastern Ontario by the afternoon and continue into the evening before tapering off around midnight. Confidence in snowfall totals here is lower, but amounts in the 5 to 10cm range appear possible by the end of the day.

While there is decent agreement on the overall track of this system, fluctuations are still very likely. Freezing rain events are among the most difficult to forecast, and even small temperature changes can have major impacts.

At this time, the highest confidence for the worst impacts remains across the Chatham, Windsor and St. Thomas area, where a persistent band of freezing rain is expected to set up for much of the day on Friday. Some models show up to 20mm of liquid precipitation, though not all of that would freeze on surfaces. For now, we are forecasting over 10mm of ice accretion, with the understanding that an overachieving scenario is still on the table.

For southern Essex County, including Leamington and possibly southern Windsor, ice accretion of 5 to 10mm is possible before a changeover to rain. Because of this transition, overall impacts should be lower compared to areas farther north, where freezing rain may last longer.

Farther north, from Sarnia through London and into Norfolk County, precipitation may begin as ice pellets in the morning before transitioning to freezing rain later in the afternoon or early evening. Ice accretion here could range from 3 to 8mm, depending on how quickly this transition occurs.

A corridor stretching from Goderich through Kitchener, Hamilton and into the Niagara region is expected to start with heavier snow Friday afternoon. Mixing with ice pellets later in the day could reduce snowfall totals, with most areas seeing around 5 to 10cm by the end of the event.

Areas that remain predominantly snow from start to finish include Grey-Bruce, much of Central Ontario, Eastern Ontario and the eastern portions of the GTA. Snowfall totals here should generally range from 10 to 15cm, with localized amounts up to 20cm. In Eastern Ontario, especially closer to the Quebec border, totals may struggle to reach 10cm, making 5 to 10cm a more realistic expectation.

We will continue to monitor the latest data closely and will have a more detailed and refined forecast on Thursday night. That update will provide a clearer breakdown of precipitation types and expected amounts. Be sure to check back for the final forecast.

December 21, 2025

White Christmas Locked In for Parts of Southern Ontario, While Others Face the Risk of a Green Christmas for 2025

December 21, 2025/ Brennen Perry

As the big day approaches this Thursday, many across Southern Ontario are starting to ask the big question. Will we wake up to that picture-perfect White Christmas, or will the Grinch sneak in at the last minute and snatch it away from right under our noses (and our carrots)?

In some parts of Southern Ontario, especially the snowbelt regions, it might feel like a White Christmas is already wrapped up and sitting under the tree. These areas were absolutely pummelled by relentless snow squalls earlier this month, leaving behind an impressive snowpack.

But for others, it has been a very different story. Some regions managed to dodge the worst of the snow so far this season, and whatever snow did fall has largely melted away thanks to a recent stretch of milder weather.

That sets the stage for a classic Christmas weather showdown. The Grinch, helped along by a few Heat Miser inspired temperature spikes, will try to erase what little snow remains. Jack Frost, however, is waiting in the wings and is expected to take over closer to Christmas. This makes a weak system expected Tuesday into Wednesday the key player, potentially delivering a last minute chance at a White Christmas for some areas.

**CURRENT SNOWFALL DEPTH (cm)** - MAP FROM WEATHERBELL

We begin by looking at the existing snowpack, which is often the biggest clue in determining where a White Christmas is all but guaranteed. The most impressive snowpack is found east of Georgian Bay through Simcoe County and into Muskoka, Haliburton and Bancroft.

Model estimates suggest a solid 10 to 25cm of snow on the ground here. These models are fairly low resolution and likely underestimate reality, especially since much of this snow fell during intense lake effect events.

There is also a respectable snowpack of around 5 to 15cm in the higher elevations of Southwestern Ontario, particularly northeast of London. These areas have taken the brunt of snow squall activity several times already this month. Meanwhile, snowpack east of Lake Huron has been noticeably reduced by the recent mild spell.

Outside of those regions, there really is not much snowpack left that can meaningfully contribute to a White Christmas. This includes Deep Southwestern Ontario, the Niagara Region, much of the Golden Horseshoe and into Eastern Ontario, including the Ottawa Valley.

**estimated max temp on tuesday** - MAP FROM WEATHERBELL

The first challenge arrives early this week as temperatures steadily rise above freezing for more than 24 hours. The warmest day looks to be Tuesday, with daytime highs climbing above freezing across much of Southern Ontario, with the main exception being parts of the Ottawa Valley.

Some areas could even push into the mid to upper single digits, especially in Deep Southwestern Ontario and around the Golden Horseshoe. That is more than enough warmth to put a serious dent in any remaining snow.

Rain may also enter the picture early Tuesday in some areas. Combined with above-freezing temperatures, this will further erode minor snowpack. At that point, the only snow that is truly expected to survive is east of Georgian Bay. For many other areas, including east of Lake Huron, the final outcome will depend heavily on the last 36 hours leading up to Christmas morning.

**NEW SNOWFALL BY CHRISTMAS MORNING (cm)** - MAP FROM WEATHERBELL

The system moving through on Tuesday is expected to bring light snowfall across Eastern Ontario. With temperatures expected to remain below freezing afterward, this snowfall should help lock in a White Christmas for the Ottawa area, even though there is currently very little snow on the ground. A general 5 to 10cm by Wednesday should be more than enough to tip the scales.

In Southwestern Ontario, however, the outlook is not as festive. Much of the snowfall associated with this system is expected to fall before temperatures rise and precipitation transitions to rain. Any snow that does fall will likely melt away quickly.

The one exception may be the higher elevations east of Lake Huron, where temperatures could hover near freezing just long enough for the snowpack to cling on until Christmas morning. Even there, it will be very close.

**estimated temp on CHRISTMAS MORNING** - MAP FROM WEATHERBELL

By Christmas morning itself, current indications suggest many across Southern Ontario will wake up to below freezing temperatures. That will help preserve whatever snow remains on the ground. This includes much of Central and Eastern Ontario, as well as higher elevations northwest of the GTA, such as Orangeville and Kitchener.

In Deep Southwestern Ontario and areas along the Lake Erie shoreline into parts of the GTA, temperatures are expected to be slightly above freezing. With very little existing snowpack to work with, those milder conditions are likely to melt away any lingering hope of a White Christmas.

Putting all of this together, we have created our preliminary White Christmas forecast. This is not the final word and adjustments are possible as we get closer to Christmas morning. Several of the uncertainties mentioned above will resolve themselves over the next couple of days, giving us a clearer picture than the models can provide right now.

Our highest confidence area, where we can almost guarantee a White Christmas with a 90 percent chance, covers a wide swath of Central Ontario, including Muskoka, Bancroft and northern and western Simcoe County. These regions have a deep, well-established snowpack. East of Lake Huron, we also assign a 90 percent chance for Hanover and much of Huron and Perth Counties, where repeated lake effect snow has buried the landscape.

Outside of that core region, we currently have a 75 percent chance for much of Eastern Ontario, along with areas such as Peterborough, Barrie and Kitchener. Confidence is fairly strong here, thanks to the existing snow southeast of Georgian Bay and the expected system snowfall in Eastern Ontario on Tuesday.

That said, melting remains a concern for Barrie and Kitchener if temperatures rise a bit more than expected on Tuesday. For Eastern Ontario, confidence also depends on the system delivering as forecast, so we want to see that snow on the ground before bumping probabilities any higher.

Closer to Lake Ontario, the dream of a winter wonderland starts to fade. From Kingston through the north GTA corridor and extending into London, we currently place the odds at around 50 percent. Along the immediate Lake Ontario shoreline, including much of the GTA, things become even more questionable with only about a 25 percent chance of a White Christmas.

For those in the Niagara Region and Deep Southwestern Ontario, including Windsor, Chatham and Sarnia, it may take a true Christmas miracle. Unless a last-minute snowmaker slides through just before Christmas morning, it looks like the Grinch may win this one.

We will continue to monitor the forecast closely and provide updates as Christmas morning draws nearer. Keep checking back, because in the weather, especially at Christmas, surprises are always possible.

December 21, 2025

Ontario: Environment Canada Forecasting Snow, Strong Winds, Cold, and Possible Freezing Rain Risk This Week

December 21, 2025/ Adam Skinner

Environment Canada meteorologists are forecasting the potential for accumulating snow, strong wind gusts, and significant cold for parts of Ontario on Tuesday. Additionally, they’re mentioning the potential for a fairly widespread freezing rain event on Friday. However, confidence is low regarding Friday at this point.

Tuesday, December 23rd, 2025

NOTE: CLICK OR TAP THE IMAGE TO OPEN A VERSION YOU CAN ZOOM

Location A: Fort Severn in Northwestern Ontario

Hazard: Cold (-40c to -45c wind chill)

Timing: Monday night into Tuesday morning

Impact(s): Risk of hypothermia and frostbite if outside for long periods without adequate protection.

Impact level: Moderate (2/4)

Confidence Level: High (3/4)

“Cold wind chill values between -40 and -45 are expected.”

Location B: Portions of northeastern, eastern, and central Ontario

Hazard: Snow (5-10cm)

Timing: Tuesday morning into the evening

Impact level: Moderate (2/4)

Confidence Level: Low (1/4)

“Snowfall amounts of 5 to 10 cm are possible. At this time, the track and timing of

the low passing through the area are still uncertain.

Possible difficult travel conditions. Snow covered and slippery surfaces such as roads and walkways.”

Location C: Areas east of Lake Superior, Lake Huron, and Georgian Bay

Hazard: Wind

Timing: Tuesday afternoon into the evening

Impact(s): Loose objects may be tossed

Impact level: Moderate (2/4)

Confidence Level: Moderate (2/4)

“Strong winds from the northwest gusting up to 80 km/h are possible.”

Friday, December 26th, 2025

Location A: Portions of northeastern and southern Ontario

Hazard: Ice

Timing: Friday

Impact(s): Possible icy surfaces such as roads and walkways. Broken tree branches from ice build-up.

“A low pressure system is expected to bring an area of freezing rain to portions of northeastern and southern Ontario. There may be 5 to 10 mm of ice accretion in areas affected by the main freezing rain band. However at this time, the track and timing of the low pressure system is quite uncertain.

Confidence is too low in the extended range to assign a weather threat level above minor. Impacts may reach moderate or greater. Watch for future updates.”

The exact track and timing of the low pressure system remain quite uncertain, meaning the freezing rain threat zone may shift in future forecasts.

In Summary

Snow and strong winds will impact much of southern, eastern, and central Ontario on Tuesday, with snowfall totals of 5-10 cm possible and winds gusts possibly reaching 70-80 km/h near Lake Huron and Georgian Bay.

Far northwestern Ontario will experience significant cold temperatures, with wind chills between -40c and -45c near Hudson Bay.

Friday brings an increasing risk of freezing rain across parts of south, eastern, and central Ontario, along with northeastern Ontario 5-10 mm of ice accretion will be possible. However, the forecast confidence remains fairly uncertain at this time as we’re several days away.

More details ASAP!

December 19, 2025

Southern Ontario: School Bus Cancellations and Closures for Friday, December 19, 2025

December 19, 2025/ Alannah Campbell

Please refresh your page every few minutes to receive the latest update

Cancellation & Closure Map (English Public and Catholic Schools)

Please note: School board boundaries are a rough estimate. Don’t use this map to determine what school board or weather zone you live in as accuracy isn’t guaranteed.

Green = No Cancellations
Red = Cancellations (Click for More Details)
Purple = School Closures (Click for More Details)

List of Cancellations & Closures

English Public and Catholic Schools

Avon MaitIand Public & Huron-Perth CathoIic: There are several closures/cancellations, please visit this link for more details: https://hpsts.mybusplanner.ca/Alerts
BIuewater Public & Bruce-Grey Catholic: All busses are cancelled.
Dufferin-PeeI Catholic: Buses to St. Andrew, St. Peter, St. Benedict as well as ALL buses to Robert F. Hall CSS are cancelled today due to weather and road conditions.
Kawartha Pine Ridge Public & Peterborough Victoria Northumberland Clarington Catholic: Bus and transportation service is cancelled to ALL schools in the STSCO jurisdiction for the day.
Near North Public & Nipissing-Parry Sound CathoIic: Bussing for all weather corridors are cancelled today.
Rainbow Public & Sudbury Catholic: All school related transportation services operating in the districts of SUDBURY, ESPANOLA, MASSEY AND MANITOULIN are cancelled today.
Simcoe County Public & Simcoe Catholic: Busses are cancelled for Muskoka.
Thames Valley Public & London CathoIic: Busses are cancelled today for Middlesex, Oxford, and Elgin Counties and Red Zone.
Trillium Lakelands: All school vehicles to schools in all Zones for Trillium Lakelands District School Board have been cancelled.
Upper Grand Public & Wellington CathoIic: All busses in Divisions 2, 3, and 4 are cancelled today.

French Schools

Conseil catholique MonAvenir: Busses are cancelled for schools in Peterborough.
Conseil scolaire catholique Providence: Busses are cancelled for Oxford, Middlesex, and Bruce-Grey.
Conseil scolaire public du Grand Nord de l’Ontario (CSPGNO): All school related transportation services operating in the districts of SUDBURY, ESPANOLA, MASSEY AND MANITOULIN are cancelled today.
Le Conseil scolaire public du Nord-Est de l’Ontario (CSPNE) & Conseil scolaire catholique Franco-Nord: Bussing for all weather corridors are cancelled today.

December 18, 2025

‘Snow Day’ Forecast: Icy Conditions Could Give Some Students an Early Start to Holiday Break Across Southern Ontario on Friday

December 18, 2025/ Brennen Perry

For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/12/19/bus-cancellations

A messy roller coaster of weather is expected across Southern Ontario throughout the day on Friday. It will begin with rain overnight, switching over to heavy snow right around the height of the morning commute. Temperatures will then plunge quickly, leading to the development of icy conditions.

To make things even more complicated, lake effect snow is expected to redevelop east of Lake Huron and Georgian Bay later in the day, with locally 10 to 20 cm of snow possible by Friday evening.

With the rain changing to snow, lining up with the morning commute and temperatures dropping through the freezing mark, there is potential for school bus cancellations, especially in rural areas.

The temperature drop is expected to be fairly gradual, which makes it uncertain whether Environment Canada will issue flash freeze warnings. That uncertainty also makes it harder to determine whether conditions will reach the threshold needed for widespread cancellations.

Our highest confidence lies in two regions that tend to be more sensitive to winter weather due to the large number of rural routes they serve. These include the North Hastings zone under Tri-Board Student Transportation Services and the Parry Sound and East Parry Sound regions within the Near North District School Board.

We have assigned these areas a 75 percent chance of bus cancellations. At this point, we are leaning toward cancellations, but not strongly enough to support a higher probability.

Across the broader rural portions of Central, Eastern and Southwestern Ontario, we have assigned a 50 percent chance of school bus cancellations, as conditions could easily go either way. We do expect several cancellations within this widespread zone.

This includes areas covered by the Avon Maitland District School Board, the Trillium Lakelands District School Board, North Bay under the Near North District School Board, Peterborough County within the Kawartha Pine Ridge District School Board, and much of Tri-Board Student Transportation Services. Kingston and Prince Edward County under Tri-Board sit lower at 25 percent. This zone also includes the Madawaska region within the Renfrew County District School Board.

Outside of these areas, there is still a slight chance of cancellations, although we are leaning toward buses running in most cases. As such, we have assigned a 25 percent chance to Lambton and Chatham-Kent within the Lambton Kent District School Board, Middlesex and Oxford counties under the Thames Valley District School Board, Dufferin and Wellington counties within the Upper Grand District School Board, the Simcoe West and Simcoe North weather zones, as well as the remaining portions of the Renfrew County District School Board and the Upper Canada District School Board.

For the rest of Southern Ontario, which is largely covered by more urban school boards, cancellations are unlikely. This includes Windsor under the Greater Essex County District School Board, London and Waterloo under the Thames Valley District School Board and Waterloo Region District School Board, the Greater Toronto Area including Toronto, Peel, York, Durham and Halton, the Simcoe Central and Simcoe South zones, and the Ottawa region.

Conditions in these areas are not expected to meet typical cancellation thresholds. Still, we have assigned a small 5 to 10 percent chance to account for the possibility of a few surprise decisions if icy conditions become more impactful than currently expected.

Disclaimer: Instant Weather has zero authority when it comes to bus and school closures.

It is completely up to the school boards, bus companies, local authorities, and parents to decide what is best for their children. This is our best guess based on our forecast.

December 17, 2025

Southern Ontario: ‘Snow/Ice Day’ Forecast for Thursday, December 18, 2025

December 17, 2025/ Brennen Perry

No major winter weather is expected across Southern Ontario on Thursday, and because of this, widespread school bus cancellations are unlikely.

That said, many areas have seen temperatures climb above freezing during the day on Wednesday, followed by an expected drop back below freezing later tonight and into early Thursday morning. This setup could allow for some localized icy conditions to develop, especially on rural roads.

Because of this possibility, we have assigned a widespread low to very low chance for an “ice day” across parts of Central and Eastern Ontario, as well as higher elevation areas of Southwestern Ontario.

We are not expecting cancellations, but if back roads become icy enough in a few localized spots, a surprise decision cannot be completely ruled out.

Disclaimer: Instant Weather has zero authority when it comes to bus and school closures.

It is completely up to the school boards, bus companies, local authorities, and parents to decide what is best for their children. This is our best guess based on our forecast.

December 16, 2025

Blizzard Conditions Expected as High Impact Winter Storm Targets the Prairies Wednesday With Up to 30cm of Snow

December 16, 2025/ Alannah Campbell

***NOTE: if you click or tap on this image you can zoom in***

The next Clipper to cross the Prairies, the latest in the seemingly never-ending train of such systems, is setting up to be the most impactful of the season so far. This system will bring 15+cm of snow to all three provincial capitals, along with blizzard conditions to parts of Southern Saskatchewan and Manitoba Wednesday and into Thursday. There has been little change in the projected track of the Clipper since we shared our preliminary forecast Monday evening so many of the details remain the same and total snowfall accumulations have become clearer.

Alberta

Snow has fallen throughout the day Tuesday in the Rockies and this will continue into the evening and overnight. Late Tuesday evening, the snow will begin to expand southeastward from Northwestern Alberta as the low pressure center associated with the system starts to make its way into the province. The leading edge of the snow will cross Alberta through the early morning hours, reaching the Saskatchewan border shortly before sunrise.

***The rdps model showing precipitation type and intensity at 5Am MT on Wednesday, courtesy of WeatherBell.***

The snow will be fairly light to moderate for most of the impacted areas of Alberta. A majority of Southern Alberta can expect less than 5cm since the precipitation will start off as a mixture of rain and freezing rain, possibly for several hours, due to the temperatures hovering around the freezing mark. However, there will be a switch over to snow as the temperatures drop, leading to the freezing of wet surfaces and minimal snow accumulation.

To the north, the lack of warm air and more consistent snowfall will result in greater accumulations. A large swath of Central Alberta and into Northern Alberta can expect 5-15cm of fresh snow, falling at rates of 1-2cm/hr during the late morning and early afternoon. In the Edmonton area and southeastward through Wainwright to the Saskatchewan border, heavier snow is expected to fall, possibly exceeding 3cm/hr, leading to rapid accumulation above 15cm.

In the early afternoon, the snow will begin to taper off from northwest to southeast across Alberta and it will gradually exit the province during the evening.

***The rdps model showing precipitation type and intensity at 12Pm CST on Wednesday, courtesy of WeatherBell.***

Saskatchewan

As the system makes its way through Saskatchewan, the situation becomes quite a bit messier. The leading edge of the precipitation will start to push through the province during the morning mostly as snow, but with rain, freezing rain, and ice pellets in the mix through the warmer air that will be present in Southern Saskatchewan. The freezing rain could last for several hours, resulting in a few millimetres of ice buildup on untreated surfaces. However, as the low tracks eastward during the afternoon, cold air will wrap around and result in a freezing of wet surfaces and a period of snow that follows.

Meanwhile, across Central Saskatchewan, as the snow moves through the province, it will intensify. Heavy snowfall rates up to 4cm/h during the afternoon and evening will result in the widespread quick accumulation of 15-30cm over an area that includes both Saskatoon and Regina.

***The rdps model showing precipitation type and intensity at 7Pm CT on Wednesday, courtesy of WeatherBell.***

Manitoba

The snow will finally start to cross into Manitoba in the late morning. There will be a much smaller pocket of warm air that will be isolated to the southwest corner of the province, so while there will be a chance for a brief period of freezing rain in Manitoba, the risk won’t be as prolonged or as widespread as in Saskatchewan.

The area of heavier snowfall will spread from Central Saskatchewan into Central Manitoba through the afternoon and evening, where it will also result in a widespread 15-30cm of fresh snow, including in Winnipeg.

During the evening, the system will begin to shift and start to track more southward as it also loses some intensity. This will bring the main band of snow into Southeastern Saskatchewan and Southern Manitoba overnight and through Thursday morning.

In Saskatchewan, the snow will taper off starting shortly after midnight and exit the province by around sunrise. The snow will continue for a few extra hours in Manitoba, starting to dissipate during the early morning hours and eventually finishing in the southeast corner of the province in the afternoon.

This only covers the snowfall aspect of this storm, but there is one major factor left to consider: the wind. Strong winds are expected to develop Wednesday morning and continue through the afternoon and evening before dying down overnight across the Prairies. We’re looking at widespread wind gusts over 60km/h and likely exceeding 100km/h, particularly in Southern Alberta and Saskatchewan. There is even the possibility of damaging wind gusts that approach 130km/h in parts of Southern Alberta!

While the most intense gusts will not coincide with the area where the heaviest snow is expected to fall, gusts above 60km/h will be more than enough for blizzard conditions to develop across Central Saskatchewan and into Central Manitoba starting in the afternoon and lasting into the overnight hours. This will likely result in large stretches of multiple highways being closed due to very poor visibility along with rapid accumulation of snow on the road surfaces.

For the rest of the region, where the wind gusts could be stronger, even a little bit of snowfall could severely impact visibility throughout the day.

Travelling in these conditions can extremely dangerous so please plan ahead, try to limit any travel, and stay safe!

December 16, 2025

Southern Ontario: ‘Snow/Ice Day’ Forecast for Wednesday, December 17, 2025

December 16, 2025/ Brennen Perry

Patchy freezing drizzle or light freezing rain is expected to develop across portions of Southwestern, Central and Eastern Ontario overnight Tuesday and into Wednesday morning.

While this freezing rain risk is not expected to be particularly impactful or widespread, it could still lead to a thin glaze of ice forming on untreated surfaces. This includes rural roads, sidewalks and vehicles, especially in areas where temperatures hover near the freezing mark through the night.

At this time, conditions are not expected to reach the threshold that would normally prompt widespread school bus cancellations. However, we cannot completely rule it out, especially if Environment Canada issues advisories overnight or if the freezing rain ends up being more widespread than currently forecast.

The most likely region to see an “ice day” is the North Hastings zone within Tri-Board Student Transportation Services. This area has a long history of being particularly cautious, largely due to its extensive network of rural routes where back road conditions can deteriorate quickly, even during relatively minor icing events. We have assigned this region a 25 percent chance to reflect that slightly elevated risk, though the overall lean remains toward buses running without major issues.

Elsewhere across the rural portions of Eastern, Central and Southwestern Ontario, we have assigned a low 5 to 10 percent chance of cancellations. Most school boards are expected to operate normally on Wednesday, but a few localized decisions cannot be ruled out depending on overnight road conditions.

This includes areas covered by Tri-Board, the Renfrew County District School Board, the Upper Canada District School Board, the Kawartha Pine Ridge District School Board, the Trillium Lakelands District School Board, the Near North District School Board, the Simcoe County District School Board, the northern portion of the Durham District School Board, the Upper Grand District School Board, the Bluewater District School Board and the Avon Maitland District School Board.

Outside of these regions, no weather-related school bus cancellations are expected on Wednesday. So for now, it looks like homework remains on the schedule.

Disclaimer: Instant Weather has zero authority when it comes to bus and school closures.

It is completely up to the school boards, bus companies, local authorities, and parents to decide what is best for their children. This is our best guess based on our forecast.

December 15, 2025

ONTARIO: Environment Canada Forecasting Snow, Flash Freezing, Heavy Rain, Strong Winds and Extreme Cold This Week

December 15, 2025/ Adam Skinner

A very active stretch of weather is expected across Ontario this week, with strong winds, snow, blowing snow, ice, heavy rain, and extreme cold all making appearances. Below is a day-by-day breakdown summary based on the latest Environment Canada forecast.

Tuesday, December 16:

- Strong southwest winds gusting up to 70 km/h for areas northeast of Lake Superior, Lake Huron and Georgian Bay, including parts of Manitoulin Island.

- Risk of flash freeze in northwestern Ontario as temperatures drop quickly, creating hidden ice on roads and walkways.

- Winds ease by late Tuesday night into early Wednesday.

NOTE: TAP OR CLICK THE IMAGE TO OPEN A VERSION YOU CAN ZOOM

Wednesday, December 17:

- Significant wind chills near -40°C in far northwestern Ontario.

- Strong winds along the northeastern shores of Lake Erie and Lake Ontario, with gusts up to 80 km/h.

- Brief burst of snow and blowing snow across northeastern Ontario as a cold front sweeps through.

- Snow spreads into northwestern Ontario later in the day and continues overnight.

Thursday, December 18:

- Strengthening low-pressure system brings 20–30 cm of heavy snow north of Lake Superior toward the Quebec border.

- Additional 5–15 cm of snow across northern Ontario.

- 15–25 mm of rain in southern Ontario on frozen ground, increasing localized flooding risk.

- Rain transitions to snow Thursday evening as temperatures fall.

- Extreme wind chills near -45°C in far northwestern Ontario.

Friday, December 19:

- A flash freeze risk across southern Ontario during the morning commute as temperatures plunge.

- Snow squalls east of Lake Huron and Georgian Bay may deliver 5‑15 cm of snow and create near-zero visibility at times.

- Additional 5‑10 cm of snow possible across northeastern Ontario.

- Extreme wind chills of -40 to -45°C persist across northwestern and far northern Ontario.

- Continued risk of frostbite and hypothermia due to the bitter cold in the northwest.

Long story slightly longer, a prolonged stretch of active weather is expected with high winds, snow, flash freezing, rain and extreme cold affecting different parts of Ontario. Stay safe and warm, everyone and make sure to download our free app InstantWeather to get the most up-to-date, detailed forecast for your specific location.

December 15, 2025

First Look at the Major Snowstorm Set to Impact the Prairies This Week

December 15, 2025/ Alannah Campbell

***NOTE: if you click or tap on this image you can zoom it***

After a seemingly constant stretch of back-to-back clippers bringing brief blasts of snow, we’re finally looking at a proper snowstorm across the Prairies this week. While this will be another clipper, it will be much more impactful, bringing periods of heavy snow to Edmonton, Saskatoon, Regina, and Winnipeg. Here’s a preliminary look at roughly what can be expected, but keep in mind that exact timing and snowfall amounts will likely change between now and the start of the event.

The snow is set to begin late Tuesday or very early Wednesday morning in the Rockies and Northern Alberta before gradually spreading eastward with the trajectory of the associated low. The leading edge of the snow will cross into Saskatchewan before sunrise Wednesday and then into Manitoba by the late morning or early afternoon.

The snowfall should be fairly moderate as it tracks across Alberta before it starts to taper off in the evening. To the east, on the other hand, the snow is expected to intensify Wednesday afternoon in Saskatchewan and in the evening in Manitoba, leading to a significant swath of up to 30cm of heavy snowfall by the noon hour on Thursday.

To complicate matters further, strong winds with gusts exceeding 100km/h are expected across the Southern Prairies beginning Wednesday afternoon and continuing overnight. This will very likely lead to white-out conditions, possibly even reaching the threshold to be considered a blizzard, in Southern Saskatchewan and Manitoba that will probably result in highway closures.

It’s also worth noting that in the warm sector, along the southern edge of the snow, there will be the possibility of a mixture of rain, freezing rain, and ice pellets which would be followed by snow as the temperatures fall. We will have more information on this risk, along with further details regarding the entire storm in our full forecast that will be posted Tuesday evening.

December 15, 2025

Southern Ontario: ‘Snow Day’ Forecast for Tuesday, December 16, 2025

December 15, 2025/ Brennen Perry

We are expecting a fairly quiet day weather-wise on Tuesday across Southern Ontario, with no major weather in place to cause widespread travel issues.

Because of this, there is nothing in the forecast that would suggest a strong likelihood of school bus cancellations.

The only area with any notable chance is the Parry Sound region under the Near North District School Board, where a snow squall warning remains in effect. That activity is expected to weaken overnight, making it questionable whether it will have any meaningful impact on the morning commute.

Even so, given this school board’s history of being particularly sensitive to weather conditions, we cannot completely rule out a surprise decision. As a result, we have assigned Parry Sound a 10 percent chance.

Outside of the Parry Sound area, no weather-related school bus cancellations are expected on Tuesday.

Disclaimer: Instant Weather has zero authority when it comes to bus and school closures.

It is completely up to the school boards, bus companies, local authorities, and parents to decide what is best for their children. This is our best guess based on our forecast.

December 14, 2025

Southern Ontario: ‘Snow Day’ Forecast for Monday, December 15, 2025

December 14, 2025/ Brennen Perry

After an active weekend that featured periods of snow squall activity across portions of Southern Ontario’s snowbelt, conditions are expected to steadily improve later Sunday evening as the lake effect weakens and winds begin to ease.

Because of this, there are no major weather concerns expected overnight that would normally keep school buses off the roads on Monday. Most regions should see calmer conditions by the time the morning bus run begins.

That said, we cannot completely rule out a few isolated cancellations tied to lingering blowing snow and rural roads that may remain snow covered following Sunday’s squalls. Any issues would be highly localized and mainly confined to areas that saw the most persistent snowfall.

If cancellations do occur, they would most likely be found in Huron County under the Avon Maitland District School Board, Middlesex County within the Thames Valley District School Board, and Lambton County for the Lambton Kent District School Board.

We have assigned these regions a 25 percent chance of a snow day on Monday to account for the potential for rural route issues. Widespread cancellations are not expected.

Elsewhere across the snowbelt, we have maintained a low to very low chance simply to account for the outside possibility of a surprise decision.

If a surprise cancellation does occur outside of the regions mentioned above, the most likely candidate would be the Near North District School Board. Some light snow and lake effect activity may redevelop there later in the day, and this board has a history of being proactive when Environment Canada issues alerts. If any alerts are in place by early Monday morning, some cancellations are possible.

For the rest of Southern Ontario, no school bus cancellations are expected on Monday. So for now, it looks like homework is back on the menu.

Disclaimer: Instant Weather has zero authority when it comes to bus and school closures.

It is completely up to the school boards, bus companies, local authorities, and parents to decide what is best for their children. This is our best guess based on our forecast.

December 13, 2025

Southern Ontario’s Never-Ending Winter Continues This Weekend as Squalls Threaten to Bring Up to 50cm of More Snow

December 13, 2025/ Brennen Perry

With a steady parade of system after system, along with lake effect snow in between, it’s certainly understandable that some parts of Southern Ontario are getting pretty fed up with all the snow. The snow continues to pile up, especially across the snowbelt regions!

It was only a few days ago that the Barrie area was slammed with intense lake effect snow, with up to 70cm reported in the hardest hit community of Angus. And that doesn’t even include what was already on the ground before this round of squalls moved through.

Regions east of Lake Huron, including Grey, Bruce, Huron and Perth counties, have also seen their fair share of snow so far this winter, with frequent lake effect events adding to an already deep snowpack.

Fortunately for snow lovers, and perhaps unfortunately for everyone else, the squalls are far from finished. The lakes remain wide open, and we are just getting into the heart of colder Arctic air. That combination will continue to provide plenty of fuel for additional rounds of lake effect snow in the coming weeks.

The next round of squalls is just around the corner, with activity expected to ramp up again as early as Saturday morning. The good news for areas that were recently hammered by the Georgian Bay squall, including Barrie and Wasaga Beach, is that you should catch a bit of a break this weekend. The bulk of the activity will focus farther north and west.

Those east of Lake Huron, including Huron, Bruce and Grey counties, are not as lucky. Lake effect snow off Lake Huron is expected to target these areas once again with repeated rounds of snow through the weekend.

This is shaping up to be a multi-day lake effect event, with squalls persisting through the weekend and possibly into Monday. Winds are expected to be somewhat unstable, which means the squalls will tend to drift around rather than remain locked over one specific area. Because of this, it’s unlikely we’ll see extreme localized totals like the 50 to 75cm that fell southwest of Barrie earlier this week.

That said, snowfall totals will still add up. The hardest hit areas, including Parry Sound, Bracebridge, Tobermory, Owen Sound, Hanover, Collingwood, Goderich and Grand Bend, can generally expect 25 to 40cm. Some pockets, particularly across Muskoka, could push closer to the 50cm mark.

The event is expected to get underway early Saturday morning as a brief southwesterly wind develops. A weak system moving through the region will become enhanced by the lakes, producing short bursts of heavy snow.

This could impact areas northeast of Georgian Bay as well as regions northeast of Lake Erie and Lake Ontario. Places like Parry Sound, North Bay, Niagara and Kingston could see a quick 5 to 10cm early Saturday morning, along with near-zero visibility at times.

As that system exits, winds will become more westerly, shifting the focus back to Georgian Bay and Lake Huron through Saturday afternoon and evening.

Current model guidance shows a fairly potent and narrow band setting up near the northern tip of the Bruce Peninsula, stretching across Georgian Bay and coming inland near Port Carling and Bracebridge. Keep in mind that even small shifts in wind direction could push the heaviest snow several dozen kilometres north or south.

Very poor to hazardous driving conditions are expected along the Highway 400 and Highway 11 corridors in this area. Highway closures are not out of the question, especially given how quickly conditions can deteriorate.

Additionally, somewhat weaker bands are also expected to develop off Lake Huron, impacting the Owen Sound to Goderich corridor. There remains uncertainty regarding exactly where these bands will set up and whether they consolidate into a more dominant squall.

Later Saturday, a subtle wind shift will cause the main Georgian Bay squall affecting Muskoka to briefly drift south into Simcoe County. This could bring a short period of heavy snow overnight Saturday to Midland, Orillia and Barrie. Accumulation here should be limited, generally around 5 to 10cm, as the squall will be moving through fairly quickly.

A similar evolution will occur east of Lake Huron, with the squall drifting from Tobermory down through the Bruce Peninsula and into southern Bruce and Grey counties overnight. This activity will continue as the squall settles farther south and west of London under a more north-northwest flow.

By Sunday morning, the strongest lake effect activity is expected to be found off Lake Huron, affecting the Grand Bend to London corridor. At this point, it appears the core of the squall should remain just west of London, impacting areas like Strathroy, though brief pushes into the city are still possible.

The Georgian Bay squall will temporarily weaken as winds become less favourable for a strong lake fetch. This should restrict activity mainly to shoreline areas near Meaford and Collingwood for a time.

That break will be short-lived. By Sunday evening, increasing winds will allow lake effect snow off Georgian Bay to intensify once again. Some models show moderate to heavy snow developing from Meaford through Collingwood and extending toward the Orangeville region overnight, before the lake effect machine is shut down by an approaching system on Monday morning.

Lake Huron squalls will continue through this time, remaining heavy at times across Huron County, Grand Bend and areas west of London. As with earlier periods, most of the heaviest snow should stay just to the west of the city.

Because the squalls will be shifting around, snowfall will be more evenly distributed across a wider area. We aren’t expecting extremely high localized totals, but many communities will still share in the heavy snowfall. By the end of the weekend, most areas east of Lake Huron and Georgian Bay could see totals ranging from 25 to 50cm.

The usual lake effect disclaimer applies. Some locations will inevitably end up just outside the heaviest bands, but the contrast should be less dramatic this time since most snowbelt areas will be impacted at some point.

The main target zones include areas east of Georgian Bay, such as Parry Sound, Rosseau, Port Carling, Bracebridge and Port Sydney, along with much of Bruce, Grey, Huron and Middlesex counties east and southeast of Lake Huron. This includes communities like Tobermory, Wiarton, Lion’s Head, Owen Sound, Meaford, Collingwood, Flesherton, Hanover, Chatsworth, Port Elgin, Kincardine, Mildmay, Point Clark, Wingham, Goderich, Clinton, Exeter, Lucan, Grand Bend and Strathroy.

Snowfall totals will drop off quickly outside of these regions, as lake effect snow remains highly localized. However, as mentioned earlier, a brief 5 to 10cm is still possible Saturday morning for parts of Niagara and the Kingston area due to lake-enhanced snow from the passing system.

For the rest of Southern Ontario, expect around 2 to 5cm from that system on Saturday, with most locations likely closer to the lower end of that range outside of the snowbelt.

Weather Forecasts & Articles

What is a blizzard?

Sunday, December 28th:

Monday, December 29th:

Tuesday, December 30th:

In summary:

Sunday, December 28th:

Monday, December 29th:

In summary:

Tuesday, December 23rd, 2025

Location A: Fort Severn in Northwestern Ontario

Location B: Portions of northeastern, eastern, and central Ontario

Location C: Areas east of Lake Superior, Lake Huron, and Georgian Bay

Friday, December 26th, 2025

Location A: Portions of northeastern and southern Ontario

In Summary

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