Toronto Snow Day Predictor & Calculator
Will TDSB or TCDSB close tomorrow?
Toronto school closures work differently than almost every other Canadian city. TDSB manages 582 schools and over 240,000 students — making its closure threshold one of the highest in Ontario. The board rarely closes for snow alone. When it does close, freezing rain is usually the reason. The Toronto District School Board snow day threshold is among the highest in Ontario.
snowdayprediction.ca reads live Environment Canada weather data and applies TDSB's documented closure behaviour to give you a snow day calculator probability score hours before the 5:30 AM announcement. Check at 9pm for an overnight read — then again at 5am for the final pre-announcement assessment. Check at 9pm for tomorrow's preliminary read — or at 5am on the morning of a storm for today's final pre-announcement probability.
TDSB Announcement Window
5:30 AM — 6:30 AM
Check back at 5am for the most accurate pre-announcement prediction. Verify here when the announcement drops.
Toronto School Boards — TDSB & TCDSB
Five school boards serve the Greater Toronto Area — each makes independent closure decisions. TDSB and TCDSB cover the City of Toronto. Peel, York Region, and Durham serve the surrounding municipalities.
Toronto District School Board
TDSB is the largest school board in Canada. Its conservative closure threshold reflects the complexity of coordinating 582 schools simultaneously — a decision that affects over 240,000 students and their families across Toronto.
Toronto Catholic District School Board
TCDSB closely mirrors TDSB closure decisions — both boards use the same road condition data and typically announce within minutes of each other. In rare cases one board closes while the other stays open during marginal weather events.
Greater Toronto Area Boards
Peel District School Board
Peel DSB serves Brampton, Mississauga, and Caledon. It closes more readily than TDSB — families in Peel should not assume TDSB's decision applies to them. Check peelschools.org independently.
York Region District School Board
YRDSB covers Markham, Vaughan, Richmond Hill, Newmarket, Aurora, King, and Georgina. York Region boards typically announce slightly later than TDSB — check yrdsb.ca directly.
Durham District School Board
DDSB serves Oshawa, Whitby, Ajax, Pickering, Clarington, and Port Perry. Durham boards close more readily than TDSB — eastern GTA families should monitor ddsb.ca separately.
Verify Here When the Announcement Drops
Always verify from official sources — predictions update hourly but announcements are final.
Toronto Bus Cancellation — TTC vs School Buses
Toronto is unique among Canadian cities — bus cancellation works differently here than anywhere else in Ontario.
TTC Almost Never Cancels
The Toronto Transit Commission operates through virtually all winter weather events. Unlike school boards in Barrie or Ottawa where bus cancellations are a regular winter occurrence, the TTC is designed for year-round urban operation. A TDSB snow day does not mean the TTC is disrupted. Families who rely on TTC to get children to school are not affected by bus cancellations — they are only affected by the school closure decision itself.
School Bus Cancellation Is Rare
Toronto school buses — operated by First Student Canada and other contractors — rarely cancel independently of a full school closure. Unlike rural Ontario boards where bus cancellations with schools open is a regular occurrence, Toronto's compact geography means road conditions that cancel buses almost always trigger a full school closure. The bus cancellation probability and school closure probability are closely correlated for Toronto.
Bottom line for Toronto families: If the snow day predictor shows a high probability, plan for a full school closure — not just a bus cancellation. In Toronto, one almost always means the other.
Toronto Winter Weather & School Closure Patterns
Why Toronto closes schools less often than cities with similar snowfall — and what actually triggers a TDSB closure.
Lake-Effect Snow — Narrower Than You Think
Toronto sits on the northern shore of Lake Ontario, which generates lake-effect snow events primarily between November and January when cold Arctic air passes over the relatively warm lake water. These events deposit 10-20cm in narrow bands, often affecting the eastern lakeshore while downtown receives nothing. The urban heat island effect means Toronto's core is typically 2-3°C warmer than surrounding suburbs, which often converts marginal snowfall events to freezing rain in the city while Barrie and Orangeville receive significant accumulation. Highway 401 and the Gardiner Expressway ice rapidly during freezing rain events — this is the primary trigger for TDSB closure decisions.
Freezing Rain Is the Real Closure Trigger
When Atlantic moisture overrides cold Arctic air over Toronto, precipitation falls as ice rather than snow. A 2mm freezing rain event on the Gardiner Expressway and Highway 401 creates conditions far more dangerous than 20cm of snow in Barrie — and TDSB responds accordingly. Environment Canada freezing rain warnings issued overnight are the single most reliable predictor of a TDSB closure. Our algorithm weights this appropriately — an active freezing rain warning over Toronto significantly increases the closure probability score regardless of snowfall totals.
Why Toronto Closes Less Than Barrie
Toronto averages just 4 school closure days per year — far fewer than Barrie (12+) or Ottawa (8-10) despite similar annual snowfall totals. The reason is infrastructure. Toronto deploys over 300 snow plows and operates a 24-hour salting operation on primary roads. Short urban bus routes clear faster than long rural routes. The Gardiner and 401 are priority corridors that receive immediate attention. TDSB can make a stay-open decision at 5:30am with confidence that roads will be safe by 7am bus time — a calculation impossible in rural Ontario.
Toronto School Closure Stats
Toronto averages 4 school closure days per year — significantly fewer than Barrie (12+) or Ottawa (8-10) despite similar snowfall totals, because TDSB sets one of the highest closure thresholds of any major Canadian board.
What to watch for in Toronto: An Environment Canada freezing rain warning issued after 8pm is the strongest signal for a TDSB closure the following morning. Snowfall alone rarely closes Toronto schools — but 15cm+ of overnight snow combined with freezing rain or wind gusts above 70km/h significantly increases the probability. Check snowdayprediction.ca at 9pm and again at 5am.
Toronto TDSB Snow Day History
Historical TDSB closure data — what storms actually closed schools and which ones didn't, and why.
The last TDSB snow day was January 17, 2022, when over 30cm fell across the GTA overnight. TDSB typically requires either 20cm or more of overnight accumulation with active road hazards, or any freezing rain accumulation on the Gardiner Expressway, to trigger a full school closure.
Notable TDSB Closure Events
Major winter storm — over 30cm fell across the GTA overnight. TDSB closed for the first time in several years for a snow event alone.
Freezing rain event — less than 2mm of ice accumulation but roads became impassable. Classic Toronto closure trigger.
20cm storm but snowfall ended at 2am giving crews 5 hours to clear. TDSB stayed open — illustration of how timing matters.
Worst Toronto winters on record for school closures
2013-2014 · 2021-2022 · 2007-2008 — these winters produced multiple closure events, including rare occurrences of consecutive closure days.
Boxing Day & Toronto School Calendar
Toronto schools are closed on Boxing Day (December 26) as a statutory holiday — this closure does not count as a weather snow day and does not affect TDSB statistics. Schools typically resume on December 27 or the first weekday after the holiday. In years where Boxing Day falls mid-week, families should check tdsb.on.ca for the exact return date. A winter storm hitting Toronto on December 26 or 27 can trigger a snow day on top of the holiday closure — snowdayprediction.ca tracks weather probability year-round including the holiday period.
Last Notable Toronto Storm Event
TDSB and TCDSB both closed. Over 30cm fell across the GTA — one of the largest snow events in recent years and a rare example of Toronto closing for snow volume alone.
Tracking Toronto closures since launch — this card updates after each recorded closure event.
Toronto Road Conditions
Gardiner Expressway · Highway 401 · Don Valley Parkway
Road conditions on the Gardiner Expressway and Highway 401 are the primary factor in TDSB bus safety assessments. Check 511on.ca for live Ontario road conditions — the same data source used by TDSB transportation assessors at 3:30am on storm mornings.
What Do Toronto Parents Think?
Will TDSB close tomorrow? Cast your vote — resets daily at midnight.
Community vote — not a prediction. Check the probability gauge above for the algorithm-based forecast.
Toronto Snow Day Tips for Parents
TDSB-specific advice based on how Toronto school closures actually work.
Watch the Rain, Not the Snow
TDSB rarely closes for snow alone. When the overnight forecast shows freezing rain — even a small amount — the closure probability jumps significantly. If Environment Canada issues a freezing rain warning after 8pm, that is your strongest signal to prepare for a snow day.
Check at 9pm and 5am
The 9pm check gives you a preliminary read to decide whether to arrange backup childcare. The 5am check — just before TDSB road assessors report in — gives you the most accurate pre-announcement read. TDSB announces between 5:30-6:30am, so the 5am probability score is your last chance to prepare before the official call.
Register for SchoolMessenger
TDSB uses SchoolMessenger to send automated notifications to registered families. If you are not registered, you will not receive the automated call or text at 6am. Register through your school's office. Follow @tdsb on Twitter for real-time announcements. 680 News and CP24 receive TDSB notifications simultaneously.
TTC Is Not Affected
A TDSB snow day does not mean TTC disruption. The TTC operates through virtually all winter weather events. If you are planning alternative childcare that involves transit, you can rely on the TTC running normally even on snow days. Check the TTC service alerts at ttc.ca for any weather-related delays.
Nearby Cities — Compare Snow Day Probability
Toronto Snow Day FAQ — TDSB & TCDSB
Toronto-specific questions about TDSB and TCDSB school closure decisions.
Does TDSB close for freezing rain?
Yes — freezing rain is actually the most common cause of TDSB closures, more than heavy snowfall. A freezing rain warning issued overnight significantly increases closure probability. Even 2-3mm of ice accumulation on the Gardiner Expressway and Highway 401 can trigger a TDSB closure when roads become impassable for buses.
What time does TDSB announce school closures?
TDSB typically announces between 5:30 AM and 6:30 AM on storm mornings. The decision is made after road condition assessors report back at 5:00-5:30 AM. Check tdsb.on.ca, their Twitter @tdsb, or listen to 680 News or CP24.
How many snow days does Toronto get per year?
Toronto averages 4 school closure days per year under TDSB — one of the lowest rates among major Canadian cities. This is not because Toronto gets little snow, but because TDSB has one of the highest closure thresholds in Ontario, reflecting the complexity of closing 582 schools simultaneously.
Does TDSB close when Peel DSB closes?
Not automatically. TDSB and Peel DSB make independent closure decisions. Peel DSB covers Brampton and Mississauga and has a slightly different threshold than TDSB. During major storms both boards typically close together, but during marginal events one may close while the other stays open.
Will the TTC run during a Toronto snow day?
Yes — the TTC almost never cancels service during winter weather events. Unlike school boards in smaller cities, Toronto's transit system is designed to operate through winter storms. A TDSB snow day does not mean TTC service is disrupted.
Is today a snow day in Toronto?
Enter Toronto in the predictor above to see today's current school closure probability for TDSB and TCDSB. If you are checking after 6am on a storm morning, the board has likely already announced — check tdsb.on.ca or @tdsb on Twitter for the official decision. For tomorrow's prediction, check at 9pm the night before.