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

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

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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.

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

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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.

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

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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.

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

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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.

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

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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.

Southern Ontario: ‘Snow Day’ Forecast for Friday, December 12, 2025

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Snow squalls that remained locked in place east of Lake Huron and southeast of Georgian Bay brought a second straight snow day to many students across the snowbelt, with school buses cancelled both Wednesday and Thursday. But for anyone hoping to turn this into a rare three-day streak and stretch the weekend a little further, the chances are not looking nearly as promising.

Through Thursday evening, the squalls have already begun to weaken, with intensity dropping off compared to earlier in the day. That downward trend is expected to continue overnight as winds ease and the lake effect snow machine gradually winds down. By morning, conditions should look much calmer, at least in terms of new snowfall.

However, despite the improvement in weather, many communities have spent the past 12 to 24 hours getting buried in persistent snow squalls. Road crews will be working hard overnight, but in the hardest-hit areas, it is unlikely that every rural route will be fully cleared by the time the morning bus run begins. Even without active squalls on Friday morning, the snow already on the ground may be enough for some school boards to consider keeping buses off the road for a third day.

Confidence in widespread cancellations is not particularly high, so we have capped the maximum at a 50 percent chance. This zone includes Huron County under the Avon Maitland District School Board, southern Bruce County within the Bluewater District School Board, and the Simcoe West zone under the Simcoe County District School Board. These regions experienced the most persistent squall activity today, and their large number of rural routes increases the likelihood that cleanup may not be fully completed by morning.

Outside this core area, a slight chance (25 percent) has been assigned to several surrounding regions. This includes Middlesex and Oxford counties within the Thames Valley District School Board, Perth County for AMDSB, the remainder of Bluewater, including northern Bruce County and all of Grey County, as well as Simcoe Central and Simcoe South. While buses should be able to run in most of these locations, the final decision will depend heavily on how effective overnight cleanup efforts are. Simcoe’s Central and South zones are also more urban, and historically, these areas require more severe conditions before cancellations are considered.

For the remainder of Southern Ontario, a snow day on Friday appears unlikely. Most regions fall into the very low to low category, with no significant weather expected overnight or Friday morning that would normally prompt cancellations. Unless there are unexpected localized issues left behind from today’s squalls, most students should plan for a regular school day.

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.

‘Snow Day’ Forecast: Snow Squalls May Deliver a Second Snow Day to Some Students in Southern Ontario on Thursday

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For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/12/11/bus-cancellations

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As snowfall from the Alberta clipper tapers off across Southern Ontario, attention quickly shifts to the next round of winter weather. Snow squalls are expected to develop off Lake Huron and Georgian Bay as early as Wednesday evening, continuing through the night and into Thursday morning.

These squalls have the potential to create dangerous travel conditions in portions of the traditional snowbelt, including Huron County, Grey-Bruce and Simcoe County. Intense snowfall rates combined with near-zero visibility may make it difficult for rural routes to be cleared in time for the morning commute. Because of this, some regions could be facing the possibility of a second straight snow day on Thursday.

The highest chance for another round of bus cancellations includes Huron County within the Avon Maitland District School Board, the Kincardine area within the Bluewater District School Board and the Simcoe West weather zone under the Simcoe County District School Board.

We have assigned these regions a 75 percent chance. While confidence is fairly strong that conditions will be poor enough to warrant cancellations, these boards have been more hesitant this season, even with strongly worded alerts from Environment Canada. That hesitation keeps this group just below the highest tier.

Surrounding regions sit in our 50 percent category, where conditions could genuinely go either way. This includes Middlesex and Oxford counties within the Thames Valley District School Board, Perth County under AMDSB and the Hanover, Southampton and Meaford areas within Bluewater. It also includes the Simcoe Central and Simcoe South weather zones. For these regions, much will depend on where the most persistent squalls set up Thursday morning. Given how lake effect snow can shift quickly, confidence stays right in the middle.

We have also assigned a 50 percent chance to parts of Eastern Ontario, including North Hastings, North Lennox and Addington and North and Central Frontenac within Tri-Board Student Transportation Services. The Madawaska zone within the Renfrew County District School Board also sits at 50 percent. Snow from the Alberta clipper may linger long enough to leave rural roads snow-covered into the morning, and these school boards tend to be more sensitive to deteriorating conditions.

A broader 25 percent zone covers the remaining rural portions of Eastern and Central Ontario. This includes the Upper Canada District School Board, the rest of the Renfrew County District School Board, the southern portions of Tri-Board, Peterborough County within the Kawartha Pine Ridge District School Board and regions covered by the Trillium Lakelands District School Board.

Snow should be wrapping up well before the bus run, but with temperatures dropping overnight and the potential for icy patches, we cannot completely rule out a few isolated cancellations. It remains questionable, but still possible.

We have also assigned a 25 percent chance to some snowbelt-adjacent communities that may be brushed by squalls at times but are expected to remain outside the core impact zone.

This includes Owen Sound and the Bruce Peninsula within the Bluewater District School Board, Dufferin County under the Upper Grand District School Board, the York Region District School Board and the Simcoe North weather zone. Occasional bursts of heavier snow are possible, but sustained conditions leading to cancellations are less likely.

Elsewhere across Southern Ontario, most school boards fall into the very low to low category. A few urban boards may keep a slight chance simply to account for any delays in overnight cleanup from Wednesday’s storm, but given that these same boards did not cancel on Wednesday, it is very unlikely they will decide to cancel on Thursday.

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.

‘Snow Day’ Forecast: Many School Bus Cancellations Likely Across Southern Ontario on Wednesday as Clipper Threatens to Dump Up to 20cm of Snow

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For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/12/10/bus-cancellations

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A strong Alberta clipper is expected to track across Southern Ontario overnight and into Wednesday. This system will bring a widespread area of heavy snowfall along with pockets of blowing snow that may significantly reduce visibility during the morning and afternoon hours.

Environment Canada has issued broad snowfall warnings ahead of the system, highlighting the potential for hazardous travel conditions throughout the day. With the most intense snowfall expected during the key morning commute window, many school boards, especially in rural regions, are likely to consider cancelling buses for Wednesday.

The highest confidence for a snow day lies across the Parry Sound and West Parry Sound regions within the Near North District School Board, along with Peterborough County under the Kawartha Pine Ridge District School Board and all regions covered by Tri-Board Student Transportation Services. These school boards have a well-established track record of cancelling when Environment Canada issues any form of winter weather warning. Because of this, we have assigned them a 90 percent chance of bus cancellations.

A large swath of Southwestern, Central and Eastern Ontario follows closely behind with a 75 percent chance of a snow day. This includes the Greater Essex County District School Board, all of the Lambton Kent District School Board, Middlesex County within the Thames Valley District School Board and both Huron and Perth counties under the Avon Maitland District School Board.

It also includes the full Bluewater District School Board, Wellington and Dufferin under the Upper Grand District School Board, Simcoe West and Simcoe North within the Simcoe County District School Board, all of the Trillium Lakelands District School Board, Northumberland County for KPR, and the full Renfrew County and Upper Canada District School Boards.

We expect most of these boards to cancel buses, although there remains a small possibility that a few may choose to operate. Snowfall amounts of 10 to 20 cm sit right on the line where some boards become hesitant, and this season, we have seen several take a stricter approach to cancellations. That uncertainty keeps this group slightly below the 90 percent tier.

For many of the province’s more urban school boards, the picture becomes less clear. These include Ottawa under the Ottawa Student Transportation Authority, Barrie and surrounding communities within Simcoe Central and Simcoe South, northern portions of the Durham District School Board, Guelph within the Upper Grand District School Board, northern Halton under Halton Student Transportation, Waterloo under Student Transportation Services of Waterloo Region, and parts of the Thames Valley District School Board covering Oxford County, Elgin County and the City of London.

Urban boards tend to require closer to 15-20 cm of snow on the ground before cancelling, and the clipper’s expected totals may fall just shy of that threshold in some neighbourhoods. Because of this, we expect roughly half of these boards to cancel and half to continue running.

For the Greater Toronto Area, confidence drops even further. Environment Canada has opted to issue a special weather statement rather than a snowfall warning, and the potential for mixing may limit totals during the morning commute. These boards, including Durham South, York Region, Toronto, Peel Region, southern Halton and Hamilton, along with Niagara, tend to be the strictest in the province when it comes to cancellations due to their lower reliance on bused students.

Here, the chance of a snow day ranges from around 10 percent in Toronto to up to 25 percent in the surrounding boards. Surprise cancellations are not impossible, but the overall lean is toward buses running.

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.

Southern Ontario: ‘Snow Day’ Forecast for Tuesday, December 9, 2025

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There are unlikely to be any school bus cancellations on Tuesday across Southern Ontario.

The only regions with any notable chance are the Bruce Peninsula under the Bluewater District School Board and areas within the Rainbow District School Board, where Environment Canada has issued a snow squall watch. However, the expected timing of the heaviest squall activity appears to fall later in the day on Tuesday, making it uncertain whether it will have much influence on the morning bus run. As a result, we have assigned a 10 to 25 percent chance for these regions.

Elsewhere, an Alberta Clipper will bring periods of light snow into Southwestern Ontario beginning Tuesday morning. Accumulation is expected to be minor and well below the threshold at which school boards typically consider cancelling buses. Even so, we have assigned a 5 to 10 percent chance to account for the outside possibility that Environment Canada issues an advisory before the morning decisions are made.

For the rest of Southern Ontario, no impacts are expected. So for now, it looks like you should plan to do your homework.

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.

Southern Ontario: ‘Snow Day’ Forecast for Monday, December 8, 2025

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With no major winter weather expected across Southern Ontario on Monday, we are not anticipating any widespread school bus cancellations.

There is, however, a low to slight chance (10 to 25 percent) for parts of Central Ontario, including regions under the Near North District School Board, as well as Muskoka and Haliburton within the Trillium Lakelands District School Board, and North Hastings under Tri-Board Student Transportation Services.

This is tied to the small possibility of cold-related cancellations. While current forecasts do not show temperatures dropping to levels that typically prompt a cancellation, if conditions trend colder overnight, a surprise decision cannot be ruled out.

We have also assigned a low to very low chance for areas near Lake Huron and Georgian Bay, where lake effect snow is still ongoing. Accumulation should taper off through the next few hours, and with totals expected to remain manageable, the likelihood of cancellations here is quite limited.

Everywhere else, we do not expect any disruptions to bus service on Monday. So tonight’s forecast is looking like you should plan to do your homework.

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.

Southern Ontario: ‘Snow Day’ Forecast for Friday, December 5, 2025

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For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/12/5/bus-cancellations

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Regions northeast of Georgian Bay are expected to see another round of snow squalls developing Friday morning and continuing throughout the day. These bands may intensify at times, creating reduced visibility and rapid snowfall accumulation.

Environment Canada has issued a snow squall watch for the area, noting the potential for 20 to 40 cm of snow. Given that setup, there is a reasonable chance that the Near North District School Board will choose to cancel buses in the hardest hit regions.

The highest likelihood is in the Parry Sound zone, which sits closest to where the squalls are expected to come ashore. We have assigned this area a 75 percent chance of cancellations. The remainder of Near North, including East Parry Sound and North Bay, is sitting at 50 percent as it is still unclear how far inland the strongest bands will extend.

We have also included a 25 percent chance for the Rainbow District School Board, focused mainly on Manitoulin Island, where the snow squall watch is also in effect. It is unlikely that the board would cancel across the entire district, so those in Greater Sudbury should expect buses to run as usual.

Elsewhere across Southern Ontario, no significant weather impacts are expected. This leaves the chances of a snow day in the low to very low range for most regions, so it may be a good idea to plan on doing your homework.

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.

‘Snow Day’ Forecast: Snow Squalls Threaten Widespread School Bus Cancellations in Southern Ontario’s Snowbelt on Thursday

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For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/12/4/bus-cancellations

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Intense snow squall activity is expected to redevelop off Lake Huron and Georgian Bay overnight and into Thursday morning. These bands may produce localized whiteout conditions and rapid snowfall accumulation. Environment Canada has issued widespread snow squall watches and warnings across much of Southern Ontario in response.

Some of the alerts in place this evening are tied to a passing frontal squall, which should weaken within a few hours and is unlikely to influence the morning bus run. The greater concern comes from the more traditional lake effect squalls expected to form overnight in the snowbelt regions, where conditions can shift from manageable to hazardous very quickly.

There is still some uncertainty regarding both timing and intensity. A few forecast models keep the squalls on the weaker side until later Thursday morning. Under normal circumstances, strong warnings from Environment Canada calling for 20 to 50 cm in the most affected areas would almost guarantee cancellations. But school boards have been particularly hesitant this year, with several opting to run buses even during significant warnings. Because of this, our overall confidence is lower than it would be in a typical setup.

The Bruce Peninsula, within the Bluewater District School Board, is the clear standout in this forecast. Conditions here are expected to be hazardous early in the morning, and the path to bus cancellations is straightforward. As a result, this region is the only one assigned a 90 percent chance.

A broader zone sits in the 75 percent category, where squalls are expected to be strong enough to justify cancellations if boards respond appropriately. This includes South Muskoka within the Trillium Lakelands District School Board, the North zone of the Simcoe County District School Board, and the Kincardine and Southampton areas in Bluewater. These regions could see rapidly deteriorating conditions right around the morning commute.

Our 50 percent “toss-up” region includes North Muskoka (TLDSB), the Town of Parry Sound (Near North District School Board), the West and Central zones of the Simcoe County District School Board, the remaining portions of Bluewater, and northern Huron County within the Avon Maitland District School Board. Travel conditions here may be poor, and squalls could strengthen faster than expected, but given this year’s track record from the boards involved, confidence in cancellations is mixed.

Farther from the core impact zone, we’ve assigned a 25 percent chance to southern Huron and northern Perth counties within the Avon Maitland District School Board, Dufferin County under the Upper Grand District School Board, Simcoe South, northern Kawartha Lakes and Haliburton within TLDSB, North Hastings within Tri-Board, and East Parry Sound under the Near North District School Board. These areas either have a history of reacting to even modest weather impacts or are positioned close enough to lake effect activity to warrant a slight elevation in risk. Still, we are not expecting widespread impacts at the time decisions are made.

Elsewhere across Eastern Ontario, the Golden Horseshoe and Deep Southwestern Ontario, the chance of a snow day remains low to very low. Snow squall activity is expected to stay well to the north and west, and urban school boards in particular are essentially at zero percent for Thursday. While a few boards on the fringe of the lake effect zones have been assigned a small chance of 10 to 25 percent in case of any unexpected morning developments, widespread cancellations outside the snowbelt remain highly unlikely.

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.

Southern Ontario: ‘Snow Day’ Forecast for Wednesday, December 3, 2025

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For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/12/3/bus-cancellations

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Snow squall activity off the northeastern shoreline of Georgian Bay has weakened substantially compared to earlier in the day, allowing Environment Canada to drop all of the warnings.

Even so, light lake effect snow is expected to persist through the overnight hours around the Parry Sound area. This could bring an additional 5 to 10 cm of snow by Wednesday morning in the most persistent bands.

Because of the earlier snowfall and the likelihood that rural roads will take some time to be fully cleared, we believe there is still a chance that the Near North District School Board may decide to cancel buses for another day.

Our confidence is not particularly high, so we have capped the probability at 50 percent for the Parry Sound region, 25 percent for East Parry Sound and 10 percent for North Bay.

Elsewhere, we are not expecting any hazardous winter weather conditions that would lead to bus cancellations on Wednesday. So it looks like you should plan to do your homework!

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.

Southern Ontario: ‘Snow Day’ Forecast for Tuesday, December 2, 2025

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For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/12/2/bus-cancellations

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Localized, intense snow squalls are expected to persist off the northern and northwestern shoreline of Georgian Bay overnight and into Tuesday morning. Environment Canada has issued snow squall warnings for the Parry Sound region, noting the potential for 20 to 40 cm of snowfall in the most intense bands.

This level of snowfall will very likely lead to bus cancellations in the hardest hit areas, which fall primarily under the Near North District School Board. We have assigned a 90 percent chance for the Parry Sound region, a 75 percent chance for East Parry Sound and a 50 percent chance for North Bay, where the impact from the squalls is expected to be more variable for those further inland.

The Bruce Peninsula, under the Bluewater District School Board, may also be affected by this lake effect activity. However, confidence is lower here, so we have gone with a 50 percent chance. Farther north, the Rainbow District School Board and the Algoma District School Board are assigned a 25 percent chance, with Manitoulin Island being the most likely area to see cancellations. The Greater Sudbury region is much less likely to reach cancellation thresholds.

In addition to the lake effect snow, a separate system is expected to track across the Northeastern United States on Tuesday. Its northern edge may bring periods of light to moderate snowfall to areas along Lake Erie and Lake Ontario, extending into Eastern Ontario during the morning hours. Accumulation will be limited, generally 4 to 8 cm closest to the U.S. border, tapering off to the northwest.

Normally, this level of snowfall would not meet the threshold for cancellations in most school boards. However, because it coincides with the morning commute, we have assigned a 5 percent chance for regions along the Lake Erie shoreline.

For Eastern Ontario, we have given a 10 percent chance to the southern portion of Tri-Board Student Transportation Services. This region tends to be more sensitive to weather conditions, and if Environment Canada were to issue any winter-related advisories, they often cancel based on that guidance. It is still a long shot, but as we saw Monday morning, this area can react quickly to even minor impacts. Other rural school boards in Eastern Ontario have a 5% chance of a snow day.

For the rest of Southern Ontario, we are not expecting any significant snow or hazardous conditions that would lead to cancellations 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.

Southern Ontario: ‘Snow Day’ Forecast for Monday, December 1, 2025

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For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/12/1/bus-cancellations

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The system that brought widespread snowfall to Southern Ontario on Sunday has now begun to move out of the region. In its place, a sharp drop in temperatures has allowed lake effect snow to develop southeast of Lake Huron and Georgian Bay.

This lake effect activity is expected to continue through the overnight hours and into Monday morning. Local snowfall totals may reach up to 15 cm in the most persistent bands. Environment Canada has issued a mix of snow squall watches and warnings for the areas most likely to be affected.

However, there is still quite a bit of uncertainty surrounding the exact intensity of these squalls and how long they will hold together. Because of this, we are not confident that conditions will reach the threshold needed to prompt widespread school bus cancellations. As a result, the highest probability on the map is capped at 50 percent along the southeastern shoreline of Lake Huron, where warnings are currently in effect and the most organized bands are expected to form.

This 50 percent zone includes southern Huron County within the Avon Maitland District School Board. It also extends into Middlesex County under the Thames Valley District School Board. These regions sit closest to the shoreline hotspot and stand the best chance of seeing stronger, more persistent squalls early Monday morning.

Surrounding this area, we have assigned a 25 percent chance for several boards that remain under a snow squall watch or tend to maintain a higher threshold for cancellations. This includes the London region of the Thames Valley District School Board and the west zone of the Simcoe County District School Board. We have also included northern Huron County and southern Perth County under the Avon Maitland District School Board, as well as the Kincardine, Southampton and Meaford regions within the Bluewater District School Board.

Temperatures are expected to fall quickly overnight, which may lead to icy and slick road conditions by the early morning commute. This is especially true in rural areas where backroads often remain snow-covered or untreated. Because of this, we have assigned a very low to low chance across rural portions of Central and Eastern Ontario. While cancellations are not expected, we cannot fully rule out a few isolated decisions if icy conditions become more impactful in rural areas.

Elsewhere across Southern Ontario, the chance of a snow day remains very low.

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.

‘Snow Day’ Forecast: Widespread School Bus Cancellations Expected in Southern Ontario’s Snowbelt on Friday

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For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/11/28/bus-cancellations

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Snow squall activity has been developing off Lake Huron and Georgian Bay throughout the day on Thursday and is only expected to intensify as we head into the overnight and early morning hours of Friday.

These snow squalls are forecast to become nearly stationary, affecting much of Grey and Bruce counties, Huron County, Perth County, Wellington County, Simcoe County and parts of the northern Greater Toronto Area.

With snowfall rates reaching 5 to 10 cm per hour in the heaviest bands, along with strong winds causing blowing snow and localized blizzard conditions, it is almost certain that school buses will be cancelled in the hardest hit regions on Friday. School closures are also possible as we are likely to see numerous road closures overnight, with conditions continuing to worsen.

We are most confident in a snow day for the southern portion of the Bluewater District School Board, along with the entire Avon Maitland District School Board. We have assigned these regions a 90 percent chance of school bus cancellations.

These areas are positioned to face the full impact of the long-lasting snow squalls through Friday morning, making it extremely unlikely that buses will be able to operate safely, especially across rural roads.

Outside of these zones, we also have fairly strong confidence in cancellations along the southeastern shoreline of Georgian Bay. This includes the Simcoe County District School Board (west and central areas), the northern section of the Bluewater District School Board, Wellington County under the Upper Grand District School Board, and the Thames Valley District School Board’s Oxford and Middlesex regions.

While confidence is high, there remains a chance that a few of these regions might attempt to run buses either because they sit just outside the core impact zone or because the school board typically has a higher threshold for cancellations. This is especially true for Simcoe County, which has been particularly strict about cancelling buses this season despite strongly worded warnings from Environment Canada. With all of that in mind, we have assigned these regions a 75 percent chance.

The probability drops off quickly outside the primary snow squall corridor. We have a 50 percent chance for the Simcoe County District School Board’s north and south areas, the Bruce Peninsula, Dufferin County, Waterloo Region under the Waterloo Region District School Board, and the London area under the Thames Valley District School Board.

In these regions, it could go either way and will largely depend on the exact positioning of the squalls. For Kitchener and London specifically, both are more urban school boards with a higher threshold for cancellations.

We have assigned a 25 percent chance for Elgin County under the Thames Valley District School Board, the Grand Erie District School Board, York Region under the York Region District School Board, the northern portion of the Durham District School Board, and the southern section of the Trillium Lakelands District School Board, including the southern City of Kawartha Lakes.

While we do not expect widespread cancellations here, if the squalls push far enough inland and produce pockets of whiteout conditions, there is still room for some surprises.

Elsewhere across Southern Ontario, there is less than a 25 percent chance of a snow day.

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.

‘Snow Day’ Forecast: Intense Snow Squall Risk Could Cancel School Buses in Parts of Southern Ontario on Thursday

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For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/11/27/bus-cancellations

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Snow squalls are expected to affect areas around Lake Huron and Georgian Bay throughout the day on Thursday. Environment Canada has issued widespread snow squall watches and warnings for the regions most likely to see hazardous conditions.

This setup raises the chances of school bus cancellations, although there is still some uncertainty because the most intense activity is expected later in the day. This puts school boards in a position where they may need to make proactive decisions early Thursday morning.

The highest chances for cancellations are in Southern Grey Bruce and Northern Huron and Perth Counties. Environment Canada has issued a strongly worded snow squall warning for these zones, highlighting the risk of very low visibility and rapid snow accumulation. Because of this, we have assigned these regions a 75 percent chance of a snow day.

Near North, which includes Parry Sound, also sits at 75 percent. This is not necessarily due to extreme snowfall expectations, but rather because that school board has historically been more sensitive to weather disruptions.

Other areas closer to the snowbelt, including TLDSB, Simcoe, Northern Grey Bruce, Dufferin, Wellington and Kitchener-Waterloo, fall into the 25 to 50 percent range. Conditions here remain somewhat variable and will depend on how the bands set up through the morning. While we are leaning toward buses running in most of these regions, there is still a decent chance that a few boards will make the proactive call to cancel.

For the rest of Southern Ontario, the chance of cancellations stays below 25 percent. Limited impacts are expected outside the traditional snowbelt, so we do not anticipate widespread issues in these areas.

Looking ahead, the chances of a snow day increase significantly on Friday. A more intense round of snow squalls is expected to develop overnight Thursday into Friday morning, bringing the strongest activity of the week right when buses would be on the roads. You can expect the next update in our snow day forecast to show much higher probabilities and quite a bit more red and pink across the map.

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.

‘Snow Day’ Forecast: Possible Bus Cancellations in Southern Ontario’s Snowbelt With Squalls Continuing Into Monday

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For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/11/17/bus-cancellations

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We’ve seen snow squalls developing off the southeastern shorelines of Lake Huron and Georgian Bay as of Sunday evening. These squalls are expected to continue through the night, and there is a good chance they will intensify as colder air pours in.

Accumulation from these squalls could reach 30 to 40cm in the hardest hit areas. With Environment Canada issuing snow squall warnings for several regions, it’s looking very likely that school buses will be kept off the roads on Monday, where conditions are at their worst.

The highest level of certainty for a snow day is southeast of Lake Huron. This is where the most intense squall activity is expected to set up and persist overnight. That includes the Exeter region of AMDSB and the Middlesex area of TVDSB. We’ve given both zones a 90 percent chance of a snow day on Monday based on the current setup.

Elsewhere in AMDSB and TVDSB, the chance of bus cancellations ranges from 50 to 75 percent. The closer a region is to the heart of the snow squalls, the higher the likelihood of cancellations. Farther out, confidence drops as it becomes less clear how far inland the heavier bands will reach.

We’ve also assigned a 50 percent chance to the Kincardine and Southampton regions under BWDSB. A weather advisory is currently in place there, but confidence is lower compared to areas southeast of Lake Huron. The snowfall might still fall short of what boards in that area need to see before pulling the plug on buses.

For the Georgian Bay snow squall, the highest risk sits in Simcoe’s west zone, including Collingwood. This area sits closest to the lake and is in the best position to see the most intense and consistent snowfall overnight. Simcoe’s Central and South zones, as well as Dufferin County, are sitting at a 50 percent chance. The main challenge here is determining whether the squall will stay strong enough as it pushes inland and exactly where that band decides to park itself.

York Region has been given a 25 percent chance, mainly for its northern sections, where some of the Georgian Bay activity could drift in. However, York tends to be more urban, and school boards in these areas are usually more cautious with cancellations, which lowers the confidence.

Much of the rest of Southern Ontario is sitting at a less than 10 percent chance of a snow day on Monday. These regions are simply too far from the lake effect zones to be significantly impacted by the squalls.

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.

‘Snow Day’ Forecast: Snow Squalls Likely to Cancel School Buses in Southern Ontario’s Snowbelt on Tuesday

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For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/11/11/bus-cancellations

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Snow squalls continue to hammer portions of Southern Ontario tonight, particularly off the southeastern shores of Lake Huron and Georgian Bay. These squalls are producing bursts of heavy snow, whiteout conditions, and rapidly changing visibility across many areas. Travel remains extremely difficult in the hardest-hit zones, and reports continue to come in of near-zero visibility and snow quickly piling up on untreated roads.

The snow machine is far from done. These intense squalls are expected to persist through the overnight hours and into Tuesday morning. As winds shift slightly eastward, the heaviest activity may drift toward London, the southern half of Huron County, and even as far east as Barrie and northern Simcoe County.

Given these conditions, Tuesday morning is shaping up to be a challenging one for school transportation in the Lake Huron and Georgian Bay snowbelts. It’s difficult to imagine buses being able to safely operate in some of these areas with such intense, localized bursts of snow and blowing snow expected to continue right into the morning.

The highest likelihood for bus cancellations will be found in regions such as Sarnia-Lambton, Middlesex, London, Exeter, Stratford, and Listowel, extending into parts of Grey-Bruce, including Meaford and Owen Sound.

These areas fall directly under the snow squall bands and have been dealing with heavy accumulation and treacherous driving conditions since Monday. We’re assigning these regions a 75 to 90 percent chance of cancellations, depending on how the squalls align overnight.

Surrounding regions, including Chatham-Kent, Elgin, Oxford, and Simcoe Central, could go either way. These areas may see lighter snow at times, but if a squall shifts slightly in their direction early Tuesday, it could quickly turn things around. For that reason, we’ve placed them around the 50 percent mark, essentially a coin flip for a snow day.

Outside of the core snowbelt, the risk for bus cancellations drops off sharply. However, there’s still a 25 percent chance for some northern GTA communities, as the Georgian Bay squall could extend farther south or east for brief periods overnight, bringing bursts of snow to places like Newmarket or northern York Region.

The Niagara region also deserves a mention. Some lake enhancement from Lake Ontario could add to snowfall totals there, though the extent remains uncertain. For now, we’re giving Niagara a slight chance of cancellations, mainly due to potential early morning slick conditions if snow bands drift farther inland.

Elsewhere across Southern and Eastern Ontario, we’re not expecting any widespread cancellations. That said, because snow squalls are notoriously unpredictable, even areas outside the main snowbelt can occasionally see quick bursts of snow that lead to surprise disruptions. For most of the GTA, though, this is likely just a regular Tuesday, so don’t count on a snow day just yet.

All in all, the best odds of getting that coveted day off from school are in the traditional snowbelt zones near Lake Huron and Georgian Bay. For everyone else, it’s back to class, but with winter tires and a little extra caution on the morning commute.

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.

‘Snow Day’ Forecast: Southern Ontario’s First Wintery Blast May Lead to School Bus Cancellations on Monday

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For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/11/10/bus-cancellations

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A system swept through Southern Ontario on Sunday, bringing with it the first widespread accumulating snowfall of the season. For many, this was the first real taste of winter, and it certainly didn’t hold back. As the system pushes eastward, snow is beginning to taper off in most regions Sunday evening, though parts of Eastern Ontario will continue to see flakes fly past midnight before conditions gradually improve Monday morning.

While the timing of this system makes it less likely to cause major issues for the Monday morning commute, there is still a chance that some regions could see school bus cancellations. The main concern will be how quickly local and rural roads can be cleared before buses head out early in the morning. Road crews will be busy overnight, but areas that received the heaviest snow or where snow continues into the early hours may still be playing catch-up by dawn.

Adding to the challenge, lake effect snow is expected to fire up behind the main system as early as Monday morning and persist through Tuesday, particularly around Lake Huron and Georgian Bay. Environment Canada has issued snow squall watches for these areas, mentioning the potential for 15 to 30 cm of additional snow, with locally higher amounts possible under stronger squalls. This could lead to sudden drops in visibility and rapidly changing travel conditions.

Because of this, some school boards near the lakes may choose to cancel buses proactively, especially where snow squall watches remain in effect. However, confidence in widespread cancellations is lower at this stage since the heaviest lake effect snow isn’t expected to fully develop until later Monday morning or afternoon.

Based on the forecast and our past experience, the highest chance for a “snow day” is across rural Eastern Ontario, particularly the Frontenac region within the Tri-Board area. We’re giving this region around a 75% chance of cancellations. Snow is expected to linger longest here, and these rural routes are typically slower to clear. The rest of the Tri-Board area, along with the Upper Canada and Renfrew regions, could go either way, earning a 50% chance depending on how quickly road conditions improve by morning.

The City of Ottawa, on the other hand, is less likely to see a snow day. Urban areas tend to handle these events better, and the overall snowfall amounts aren’t expected to reach the threshold that usually triggers cancellations. Still, we’ve placed Ottawa at a 25% chance, since it’s the first major snowfall of the season and even modest totals can cause delays if cleanup efforts fall behind overnight.

Across Southwestern Ontario and the Lake Huron snowbelt, bus cancellations are also possible, especially as snow squalls intensify through the day. School boards such as LKDSB, TVDSB, AMDSB, and BWDSB could see anywhere from a 50% to 75% chance of cancellations, depending on where the lake effect bands set up. The heaviest and most persistent squalls are expected along and just inland from the shoreline, particularly around Grand Bend, Strathroy, and Petrolia. The Simcoe West and Meaford areas could also be affected by Georgian Bay lake effect activity, where we’ve assigned a 50% chance.

Outside of Eastern Ontario and the lake effect zones, the risk of a snow day drops off significantly. Most of the Golden Horseshoe, Niagara, and Southwestern Ontario should have more than enough time for roads to be cleared before the morning commute.

That said, temperatures will dip below freezing overnight, which could cause refreezing of slushy or untreated surfaces and create localized icy patches. Even where cancellations aren’t expected, drivers should plan for slower travel Monday morning.

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.