Ontario Snow Day Predictor
Type an Ontario city or town for the chance snow, ice or cold closes school or cancels buses on the next school morning
An estimate from the forecast, not a promise.
Looks like a regular school day. Check again if the forecast changes.
- Overnight low
- —
- Snow
- 0.0 cm
- Freezing rain
- 0 hrs
- Max gust
- 0 km/h
🧪 Test weather, not the real forecast
In much of Canada, school buses can be cancelled while schools stay open. This is a weather estimate, not an official bus cancellation; check your school board or bus service.
Opens a web search in a new tab. Only your school board can say for sure.
Next 5 school days
Days 3–5 are an early outlook and may change. School holidays aren’t known.
More weather details
7 am temperature: —
No snow or ice expected overnight
Hour by hour
Why this number?
Overnight window: 6 pm – 8 am before school.
What decides a snow day in Ontario
Your school board does, usually together with its bus consortium, and most boards post the call by about 6 to 6:30 a.m. In most of the boards we checked, a cancelled bus doesn’t close the school: the buses stop, but classrooms stay open.
OCDSB says Ottawa’s bus authority weighs the type of precipitation, how long it’s forecast to last, how much is expected and the air temperature, across its whole service area. Cold can be enough on its own: Waterloo Catholic’s procedure says that when the wind chill is forecast at −35°C or colder at 7 a.m., buses won’t run but schools stay open. This Ontario snow day calculator reads the forecast the same way, for overnight snow, freezing rain, cold at 7 a.m. and gusty wind.
School boards
What 12 Ontario school boards do when buses are cancelled
We read each board’s own page in October 2026 and quote it below. Seven say or show that schools can stay open when buses are cancelled, and Waterloo Region says a cancellation doesn’t automatically close schools. Hamilton-Wentworth is the exception: severe weather plus a bus cancellation closes its schools. Durham’s notices have gone both ways, Waterloo Catholic’s written rule covers frigid cold only, and we couldn’t read TCDSB’s own page.
| Board | When buses are cancelled | Buses run by | When and where it’s announced |
|---|---|---|---|
| Toronto DSB (TDSB) | “If school buses are cancelled, it is still possible for students to get to school by walking or other means”; about 93% of students don’t use buses | Toronto Student Transportation Group, shared with TCDSB | By 6 a.m. on the TDSB website and social media |
| Toronto Catholic DSB (TCDSB) | Check the board’s page | Toronto Student Transportation Group, shared with TDSB | Check the board’s page |
| Dufferin-Peel Catholic DSB | “If buses are cancelled in a certain zone/region, schools will remain open to staff and students.” | Student Transportation of Peel Region (STOPR); three Dufferin County schools use STWDSTS | By 6:00 a.m. or shortly afterwards, on STOPR’s site, the board’s website banner and its social media |
| York Region DSB | “Schools will remain open unless otherwise stated, even when buses have been cancelled.” | Student Transportation Services of York Region | By 6:00 a.m., on board and school websites, @YRDSB on X, Student Transportation Services’ website and hotline, and local radio and TV |
| Durham DSB | It depends: on February 18, 2026 buses were cancelled in all zones and “All schools are open”; on February 13, 2025, “All schools are closed.” | Durham Student Transportation Services | Check the board’s page; notices appear in its School Closures and Bus Cancellations news |
| Halton DSB | “If buses are cancelled but schools remain open, in-person and e-learning courses will continue as scheduled.” | Halton Student Transportation Services | By 6:30 a.m., on the HDSB website, app and social media, by email and on local TV and radio |
| Ottawa-Carleton DSB | On a snow day, yellow buses are cancelled and “All schools remain open for students.” | Ottawa Student Transportation Authority (OSTA) | OSTA decides between 4:00 and 5:30 a.m.; check the OSTA or OCDSB websites |
| Hamilton-Wentworth DSB | “Severe weather + Bus cancellation = Schools and Administrative Buildings are closed” | Hamilton-Wentworth Student Transportation Services | By 6 a.m., by email to families |
| Waterloo Region DSB | “Bus cancellations do not automatically result in schools being closed.” | Student Transportation Services of Waterloo Region (STSWR) | By 6 a.m. on wrdsb.ca and its social media; nothing posted by then means a regular school day |
| Waterloo Catholic DSB | In frigid cold (−35°C or colder with wind chill at 7 a.m.), “Buses will not operate, but schools will remain open.” Closing a school depends on other factors. | STSWR, shared with WRDSB | The WCDSB website, its social media and local radio |
| Simcoe County DSB | “When buses are cancelled SCDSB schools remain open for student learning.” | Simcoe County Student Transportation Consortium (SCSTC) | SCSTC aims to post between 6 and 7 a.m., on its website, its Twitter account and local radio |
| Thames Valley DSB | “In most cases, when buses are cancelled, schools remain open.” | Southwestern Ontario Student Transportation Services | Check the board’s page; bus delays and cancellations are posted at mybigyellowbus.ca |
“Check the board’s page” means the page we read doesn’t say. TCDSB’s site wouldn’t load for us; the consortium it shares with TDSB is named in TDSB’s transportation policy. The Peel District School Board’s site wouldn’t load either, so it isn’t listed; Dufferin-Peel says STOPR was formed by both Peel boards. For Simcoe County, SCDSB’s page says 6 to 7 a.m., while the consortium’s own site, quoted on our Barrie page, says 6:00 to 6:30 a.m.
Provincial rule
A weather closure still counts as a school day
When Ontario schools do close for weather, the day isn’t lost. Section 6 of Ontario Regulation 304 says that when a school or class closes for inclement weather or a failure of transportation arrangements, “the day on which the school or class is closed remains an instructional day.”
We found no rule that makes families or schools make those days up. Our guide How many snow days do schools get? covers Ontario’s 194-day school year and how it compares with US states.
Method
How the Ontario estimate works
Type a town and the calculator runs the published snow day formula for that town’s next school morning, in °C, cm and km/h:
- Overnight snow is the main factor, from about 8 points for 1 cm to about 70 for 15 cm or more, and half that if 7 a.m. is warmer than about 1°C.
- Freezing rain adds 30 to 65 points. A 7 a.m. temperature of −18°C or colder adds 10 (20 at −26°C), and gusts of 48 km/h or more add 10 to 15 when there’s snow or ice.
- The chance is held between 1% and 99%: Likely from 60%, Maybe from 30%, and No Chance below that.
Our points haven’t been checked against any Ontario board’s past decisions, so we can’t say how accurate they are here. Read a high number as a rough morning for buses. Whether schools close is the board’s call, and the table shows most boards keep them open.
FAQ
Ontario snow day questions
Will there be a snow day in Ontario tomorrow?
It depends on your board, and nobody knows until it posts the call, usually by about 6 to 6:30 a.m. Type your town in the calculator above for a forecast-based estimate of tomorrow’s chance, then check your board and bus consortium in the morning.
If buses are cancelled, is school closed in Ontario?
Usually not. Of the 12 boards in our table, seven say or show that schools can stay open when buses are cancelled, and Waterloo Region says a cancellation doesn’t automatically close schools. Hamilton-Wentworth is the exception: severe weather plus a bus cancellation closes its schools.
What time are Ontario snow days announced?
Most boards we checked post by 6 a.m., including TDSB, York Region, Dufferin-Peel, Hamilton-Wentworth and Waterloo Region. Halton’s deadline is 6:30 a.m., and in Ottawa the bus authority decides between 4:00 and 5:30 a.m.
Do Ontario schools make up snow days?
No rule requires it. Ontario’s Regulation 304 says a day a school is closed for inclement weather remains an instructional day.
Can I check any Ontario town, or a postal code?
Any city or town name works, like “Sudbury” or “Peterborough”, and Ontario towns are searched first. Postal codes and street addresses can’t be looked up yet, so type the town instead.
How accurate is this Ontario snow day forecast?
We don’t know yet. The formula hasn’t been compared with past decisions by any Ontario board, so treat the number as a forecast-based estimate, not a prediction of what your board will announce.
Is this an official Ontario source?
No. This site isn’t connected to the Government of Ontario, any school board or any bus consortium. Their announcements are the answer.