Canada's Snow Day Predictor
& Calculator
Most Canadian parents find out about a snow day the same way — a phone buzzing at 6am with a SchoolMessenger notification, already too late to make a plan. Canada's snow day predictor gives you the school closure probability for your city hours before your board makes that call.
snowdayprediction.ca reads live Environment Canada weather data through a 9-variable scoring algorithm calibrated to your specific school board's closure history. A 15cm overnight forecast means something very different for the Toronto District School Board than it does for the Simcoe County District School Board in Barrie — and our prediction reflects that difference. Enter your city. Get your probability. Plan your morning before midnight.
How the Snow Day Predictor Works
The snow day calculator runs four steps every time you search — from raw Environment Canada data to a board-calibrated probability score in seconds.
Enter Your City
Type any Canadian city name. The tool identifies your school board automatically — covering every major board from TDSB in Toronto to CBE in Calgary to HRCE in Halifax. No postal code required.
We Pull Live Environment Canada Data
The scoring engine fetches the latest forecast from Environment Canada's Meteorological Service — the same official data source your school board uses when making its closure decision. Data updates every 30 minutes during active weather events.
9 Variables Run Through the Algorithm
Overnight snowfall (27%), storm timing (20%), precipitation type — snow vs freezing rain vs mixed (19%), wind chill (17%), active Environment Canada warnings (10%), and wind speed (7%) are weighted and scored. A board-specific multiplier and historical trend modifier then adjust the result for your exact school board.
Your Snow Day Predictor Score
You receive a probability between 0% and 98%, displayed on a colour-coded gauge: green (unlikely), blue (possible), orange (likely), red (very likely). The score reflects your board's actual closure behaviour — not a generic national estimate.
When Do Canadian Schools Announce Snow Days?
Understanding the timeline helps you know exactly when to check — and why a 9pm prediction is different from a 5am one.
Road Assessors Deploy
School board road condition assessors drive primary bus routes, reporting pavement conditions, ice presence, and visibility back to transportation superintendents. This is the data that drives the final decision — not the weather forecast alone.
Superintendent Reviews Reports
Road assessor reports arrive. The superintendent of transportation cross-references them with the Environment Canada forecast and makes a closure recommendation. For overnight storms, many boards have already issued a Storm Watch notice at 10pm the night before.
Final Decision Made
The board director or designate makes the official closure decision. At this point the outcome is locked — no further weather changes affect it. This is why checking our predictor at 5am gives you the most accurate pre-announcement reading.
SchoolMessenger Calls Begin
Automated SchoolMessenger notifications go out to registered families. Local radio stations — CBC, Newstalk, CJAD — receive board notification lists simultaneously. Board websites update by 6:15am. By 6:30am the information is everywhere.
Best times to check snowdayprediction.ca
9:00 PM the night before — preliminary read based on overnight forecast. Accurate for major storms. Use this to decide whether to arrange backup childcare. 5:00 AM on storm morning — final pre-announcement check. The overnight forecast has fully updated. This is our most accurate window, immediately before boards make their call.
How Much Snow Causes a Snow Day in Canada?
Snowfall thresholds differ significantly across Canada. What closes schools in Halifax would barely register in Calgary. Here is what actually triggers closures by region — based on historical board behaviour.
Ontario — Urban Boards (TDSB, Peel DSB, OCDSB)
Urban Ontario boards typically require 15cm or more of overnight accumulation before closing. Urban road infrastructure, plowing capacity, and short bus routes mean moderate snowfall is manageable. Freezing rain overrides this threshold — even 3mm of ice accumulation triggers closure regardless of snowfall totals.
Ontario — Rural Boards (SCDSB, TVDSB, KPRDSB)
Rural Ontario boards close at lower accumulations — often 10cm — because long rural bus routes cover unpaved roads that ice and drift faster than urban streets. Barrie's SCDSB is particularly sensitive to Georgian Bay lake-effect events, which can deposit 20cm+ in hours while Toronto receives nothing.
Prairie Provinces (CBE Calgary, EPSB Edmonton, WSD Winnipeg)
Prairie boards have the highest snowfall tolerance in Canada — typically 25cm or more — because infrastructure is built for heavy snow. The trigger on the prairies is not snowfall but wind chill: temperatures below -40°C with wind chill close schools for cold safety regardless of whether any snow has fallen.
Atlantic Canada (HRCE Halifax, ASD-S, NLESD)
Atlantic boards close at relatively low accumulations — 8–12cm — but freezing rain is the dominant trigger. Halifax roads on hilly terrain become impassable with as little as 5mm of ice accumulation. Atlantic boards also close more readily during high wind events even without significant snow.
British Columbia — Coastal (VSB Vancouver, Surrey Schools)
Coastal BC boards have the lowest snowfall tolerance in Canada — as little as 3–5cm on hills triggers closures. Vancouver has minimal de-icing infrastructure because heavy snow is rare. When it does fall, steep residential streets become dangerous faster than anywhere else in Canada.
Quebec (CSSDM Montréal, EMSB, CS de la Capitale)
Quebec boards sit between Ontario urban and rural thresholds — typically 15–20cm for major urban boards. Quebec applies a province-wide protocol for extreme cold alerts, and its French-language boards sometimes operate on different timelines than English boards in the same city. Our French predictions at /fr/quebec/ account for this difference.
Important: Snowfall amount is the starting point — not the deciding factor. Storm timing matters more than accumulation in most closure decisions. A 10cm storm ending at 2am gives road crews 4+ hours to clear before buses run. The same 10cm arriving at 5am is a closure. Our algorithm accounts for timing as a weighted variable — something no other Canadian snow day calculator does.
Snow Day Predictions Across Canada
Every province page lists the major school boards, their announcement times, how they communicate closures, and links to every city we cover in that province.
Why snowdayprediction.ca Is Different
Every weather app will tell you a storm is coming. Only a board-calibrated predictor tells you whether your specific school will act on it.
Built for Canadian Schools — Not American Tools
The most popular snow day tools were built for American school districts with American weather thresholds and American bus safety standards. When a Canadian parent uses those tools, the prediction is calibrated for Philadelphia or Detroit — not Toronto or Barrie. snowdayprediction.ca was built from the ground up for Canada, using Canadian board data, Canadian weather models, and Canadian closure patterns.
Board-Calibrated — Not One-Size-Fits-All
A 10cm snowfall means something very different to SCDSB in Barrie — where Georgian Bay lake-effect storms are routine — compared to TDSB in Toronto, where 10cm is significant but urban infrastructure keeps roads passable. Our scoring engine applies a unique boardMultiplier to every prediction, reflecting each board's documented closure behaviour over multiple winters.
9 Variables vs. Basic Snowfall Totals
Most snow day calculators look at how much snow is forecast. snowdayprediction.ca runs nine weighted variables — including storm timing, precipitation type, active Environment Canada warnings, and wind chill — because Canadian boards make closure decisions based on all of these factors simultaneously, not snowfall alone.
Not AccuWeather — A School Closure Interpreter
AccuWeather tells you a storm is coming. snowdayprediction.ca interprets that storm through the lens of your school board's closure history. AccuWeather says 20cm is forecast for Barrie. snowdayprediction.ca says there is a 78% chance SCDSB closes — because that specific board has closed 8 of the last 10 times Barrie received 15cm+ overnight. These are fundamentally different tools serving different needs.
French Quebec Coverage — No Competitor Has This
snowdayprediction.ca is the only Canadian snow day predictor with dedicated French-language pages for Quebec cities at snowdayprediction.ca/fr/quebec/. Quebec's French-language school boards — centres de services scolaires — operate on different protocols than English boards. Our French predictions account for these differences. Eight million Quebecers. Zero French coverage from any competitor.
Free, Private, No Account Required
No email address. No account. No subscription. City names are used only to identify your school board — they are not stored or shared. snowdayprediction.ca will always be free for Canadian parents, students, and educators.
Bus Cancellation Is Not the Same as a Snow Day
Most snow day tools ignore this distinction. For rural families, it is the most important one.
Bus Cancelled — School Open
Canadian school boards regularly cancel bus transportation while keeping schools open. This happens when road conditions make bus routes unsafe but school buildings remain accessible for families who can drive. In Ontario, SCDSB and TVDSB cancel buses independently of school closure decisions multiple times per winter. For urban parents, this rarely matters. For rural families, a bus cancellation with school open means no school that day regardless — because there is no other way to get there.
How We Show Both Probabilities
Every city page on snowdayprediction.ca shows two separate indicators: the school closure probability and the bus cancellation probability. Bus cancellation scoring weights road condition indicators and wind chill more heavily than the school closure score, reflecting how transportation departments make decisions independently of superintendents. No other Canadian snow day calculator separates these two decisions.
Check your city page for the bus cancellation probability specific to your school board's transportation operator — separate from the school closure prediction.
Who Uses the Snow Day Predictor?
Snow days affect everyone connected to Canadian schools. Each group uses the predictor differently — and needs different information at different times.
For Parents and Guardians
Plan Your Day Before Midnight
Check the prediction at 9pm the night before to decide whether to arrange backup childcare, notify your employer, or adjust your work-from-home schedule. When the predictor shows 75% or higher, having a plan ready before you sleep eliminates the 6am scramble. The bus cancellation indicator tells rural parents what they actually need to know — school open is irrelevant if the bus is not running.
For Students
Know Before You Set Your Alarm
A high probability score the night before tells you whether to finish that assignment tonight or set a cautious backup alarm for 6am. A percentage above 70% does not guarantee a snow day — your board makes the final call — but it gives you the best available read on what is likely to happen based on your board's documented closure history.
For Teachers and School Staff
Prepare Before the Announcement
A 70%+ prediction the night before is a practical signal to prepare flexible lesson plans, load online materials, or set up alternate activities. snowdayprediction.ca gives you the same advance read your students are already checking — the difference is using it to prepare rather than just to hope.
What Else Should Canadian Parents Know About Snow Day Predictions?
The most common assumption about snow days is also the most wrong one.
Storm Timing Closes More Schools Than Snowfall Amount
Most people assume the amount of snow determines whether school closes. Canadian board data tells a different story. Storm timing — specifically when snowfall peaks relative to the morning bus run — consistently outweighs accumulation totals in closure decisions.
A 10cm storm ending at 2am gives road crews more than four hours to clear primary bus routes before the first pickup at 7am. That same 10cm arriving at 5am — with plows just starting their first pass — almost always triggers cancellations across rural Ontario, Atlantic Canada, and the Prairies. Same snowfall amount. Completely different outcome.
This is why checking a snow day predictor that only looks at forecasted snowfall totals gives you an incomplete picture. Our storm timing variable carries a 20% weight in the scoring algorithm — second only to overnight snowfall at 27% — precisely because Canadian transportation departments weight it so heavily in their own assessments.
Practical implication: A forecast showing 8cm arriving between 4am and 7am is a higher-probability snow day scenario than 15cm arriving between 8pm and midnight — even though the second storm drops nearly twice as much snow. Our predictor reflects this. Most calculators do not.
Pour nos utilisateurs québécois
Vous cherchez en français?
Nos prédictions pour les écoles québécoises sont disponibles en français — avec des données calibrées pour les centres de services scolaires francophones.
Frequently Asked Questions — Snow Day Predictor
Everything Canadian parents, students, and teachers ask about how the prediction works.
Will there be a snow day tomorrow?
Enter your city in the snow day predictor above to see tomorrow's school closure probability for your specific school board. The prediction pulls live Environment Canada data and updates every 30 minutes. For the most accurate read, check at 9pm for a preliminary result and again at 5am for the final pre-announcement assessment.
How accurate is the snow day predictor?
snowdayprediction.ca achieves 85–92% accuracy for major storm events involving 15cm or more of overnight snowfall. For marginal events — 5 to 10cm with mixed precipitation — accuracy is 70–75%, reflecting the genuine uncertainty in board decision-making during those conditions. Accuracy is highest when checked at 5am, after the overnight forecast has fully updated and road assessors have begun their rounds.
What are the chances of a snow day today?
Enter your city above to see the current probability for today or tomorrow. The tool displays the school closure probability for the upcoming overnight window — the period between 11pm and 7am that determines whether roads are clear by bus time. If you are checking after 6am on a storm day, check your school board's website or local radio for the official announcement directly.
How much snow causes a school closure in Canada?
Thresholds vary significantly by province and board. Ontario urban boards typically close at 15cm or more. Prairie boards require 25cm or more because infrastructure handles heavy snow routinely — but wind chill below -40°C closes schools regardless of snowfall. Atlantic boards close at 8–12cm, with freezing rain the dominant trigger at as little as 5mm of ice accumulation. Coastal BC boards close at 3–5cm because de-icing infrastructure is minimal. Storm timing also matters — the same snowfall amount produces different outcomes depending on when it arrives relative to the morning bus run.
Does the snow day predictor work for all Canadian provinces?
Yes — all 10 provinces and 3 territories are covered. Ontario and Quebec have the deepest board-level calibration with individual boardMultiplier values for major boards. All other provinces use regional weather data cross-referenced with publicly available board closure history. French Quebec predictions are available at snowdayprediction.ca/fr/quebec/ with content calibrated specifically for francophone school boards.
How is this different from AccuWeather for snow day predictions?
AccuWeather delivers a weather forecast. snowdayprediction.ca interprets that forecast through each Canadian school board's specific closure behaviour. AccuWeather tells you 20cm is forecast for Barrie. snowdayprediction.ca tells you there is a 78% chance SCDSB closes — based on how that board has responded to similar conditions historically. Weather forecasts and school closure predictions are fundamentally different outputs from fundamentally different data models.
If buses are cancelled, is it a snow day?
Not automatically. Canadian school boards regularly cancel bus transportation while keeping schools open. For families who can drive, school is still in session. For families who depend on the bus — particularly in rural areas — a bus cancellation effectively means no school that day. snowdayprediction.ca shows both the school closure probability and the bus cancellation probability separately on every city page.
Popular Cities — Check Your Snow Day Probability
Jump directly to your city's prediction page for board-specific school closure probability, bus cancellation indicator, and school board announcement times.