Ontario Snow Day Predictor
Will Ontario schools close tomorrow?
Ontario has 72 school boards serving 2 million students across one of the most geographically diverse provinces in Canada. Snow day decisions are made independently by each board — Toronto's TDSB closes 3 to 5 times per year while Barrie's SCDSB closes 12 to 15 times. The difference is geography, not weather tolerance.
snowdayprediction.ca calibrates each Ontario city prediction to the specific school board covering that community — closure thresholds, geographic footprint, bus operator cancellation patterns, and historical closure frequency are all factored into the probability score. This school closures predictor and school day predictor updates hourly — giving Ontario parents an early read on snow day odds before the 6:00 AM board announcements.
Ontario Snow Day Predictor — By City
Select your Ontario city for a real-time school closure probability calibrated to your school board. Use this snow day map of Ontario to find your city and check the current closure probability for your school board.
How Ontario School Boards Decide Snow Days
The process is consistent across Ontario boards — the thresholds and geographic factors differ.
Transportation Assessors Drive Key Routes
Ontario school board transportation assessors begin driving designated rural routes at 3:00 AM on storm mornings. These assessors report road conditions, visibility, and ice accumulation directly to board transportation directors. Rural county roads are assessed first — they are almost always the deciding factor.
Bus Operators Report In
Student transportation operators report road condition assessments to school boards between 4:00 and 5:00 AM. When a transportation operator cancels routes region-wide, the school board almost always follows with a full closure announcement. A bus cancellation is the single strongest predictor of a school closure. This is why our school bus predictor and school bus cancellations predictor tracks bus operator status alongside weather data — a region-wide bus cancellation is the strongest leading signal for a school closure.
Board Announces the Decision
All major Ontario school boards target a 6:00 AM announcement — TDSB, OCDSB, HWDSB, WRDSB, TVDSB, SCDSB, and UGDSB all follow this window. Announcements appear simultaneously on board websites, Twitter accounts, and local radio stations. The 5:00 AM check on snowdayprediction.ca gives parents the most accurate pre-announcement probability.
What Actually Closes Ontario Schools
Overnight snowfall above 15cm is the primary closure trigger across most Ontario boards. Freezing rain warnings are equally reliable — even 5mm of ice on rural county roads causes closures. Visibility below 400 metres during the morning commute window triggers closures regardless of snowfall totals. Wind chill below -40°C also triggers closures in northern Ontario boards.
Ontario School Board Snow Day Comparison
Closure frequency varies dramatically across Ontario — geography drives the difference more than weather severity.
| Board | City | Avg Closures/Year | Primary Driver |
|---|---|---|---|
| SCDSB | Barrie | 12–15 days | Lake Huron + Georgian Bay lake-effect |
| OCDSB | Ottawa | 8–12 days | Arctic air mass · Quebec border exposure |
| TVDSB | London | 8–10 days | Lake Huron + Lake Erie dual exposure |
| HWDSB | Hamilton | 6–8 days | Lake Ontario · Niagara Escarpment |
| WRDSB | Kitchener | 6–8 days | Alberta clippers · rural Waterloo County |
| UGDSB | Guelph | 6–8 days | Dufferin County elevation · rural routes |
| TDSB | Toronto | 3–5 days | Urban road clearing · no rural routes |
Why rural boards close more: Ontario school boards covering large rural footprints close at lower snowfall totals than urban boards. A 12cm snowfall that leaves Toronto schools open will close Barrie, Ottawa, and London schools because rural county roads receive lower plowing priority and deteriorate faster than urban arterials.
Ontario Snow Day FAQ
Common questions about Ontario school closures and the snow day prediction process.
Will there be a snow day tomorrow in Ontario?
Snow day decisions in Ontario are made by individual school boards — not the province. Each board announces closures by 6:00 AM based on road conditions, Environment Canada forecasts, and bus operator reports. Use snowdayprediction.ca to check the closure probability for your specific Ontario city and school board.
How do Ontario school boards decide snow days?
Ontario school boards assess road conditions starting at 3:00 AM through transportation assessors who drive key routes. When bus operators cancel routes region-wide, boards typically close all schools. Snowfall above 15cm overnight and freezing rain warnings are the primary closure triggers across most Ontario boards.
What time do Ontario school boards announce closures?
Most Ontario school boards announce closures by 6:00 AM. TDSB, OCDSB, HWDSB, WRDSB, TVDSB, SCDSB, and UGDSB all target the 6:00 AM announcement window. Local radio stations and board websites are the fastest verification sources.
Which Ontario cities get the most snow days?
Barrie and Simcoe County average 12 to 15 school closure days per year — the highest in Ontario — due to Lake Huron and Georgian Bay lake-effect snow. Ottawa averages 8 to 12 days due to Arctic air mass exposure. London averages 8 to 10 days from dual Lake Huron and Lake Erie exposure. Toronto averages 3 to 5 days as the least affected major Ontario board.
Is there a chance of school closing tomorrow in Ontario?
Check the city grid above for your board's current snow day odds. Each city page shows a live probability score calibrated to that board's closure threshold. For TDSB snow day tomorrow predictions specifically, check the Toronto page — TDSB announces by 6:00 AM and our predictor gives you an early read the night before.
Looking for a city not listed above? Use the snow day predictor tool on the homepage to search any Canadian city.
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