Northeastern Ontario · In centimetres
Snow Day Predictor Greater Sudbury
Will school be closed tomorrow?
Loading Greater Sudbury's live forecast now. Tuned for what actually closes schools here — heavy snow and extreme cold together.
Greater Sudbury Closure Chance
In Ontario a bus cancellation is the likelier outcome — check the bus cancellation predictor for that.
What Closes Schools in Greater Sudbury
Sudbury gets both problems at once. It takes serious snowfall through the winter and it gets genuinely dangerous cold, and either one on its own can pull buses off the road before a single flake needs to fall.
Greater Sudbury covers an enormous area — over 3,000 square kilometres — so a single board runs bus routes across rock, lake and bush for very long distances. Conditions on a route forty minutes outside the city centre routinely differ from downtown, which is why zone-by-zone cancellations are normal here rather than exceptional.
What a Bad Morning Actually Looks Like
A bad Sudbury morning is often not about the snow at all. It is minus 38 with the wind, the sky is clear, and the question is whether a child on a route out past Chelmsford or Skead can safely stand at a stop with no shelter for fifteen minutes. On those mornings the roads are perfectly drivable and the buses still do not run.
How Much Snow It Takes Here
Snowfall alone has to be substantial — 20 cm or more — before closures come into play, because the city is thoroughly equipped for winter. Extreme cold is the more common trigger: at roughly −35°C to −40°C wind chill buses are pulled regardless of snow.
Sudbury needs a lot of snow before depth alone changes anything, so watch temperature first. When it does snow heavily, timing still decides it: a band that clears by 2am is a plowed road by 6. Beyond that, snow still falling between 3am and 8am counts for several times its depth, because the pre-dawn road patrol is what the decision is built on.
In Greater Sudbury, Expect the Buses to Go First
Ontario boards rarely close schools. What happens instead is that the student transportation consortium cancels buses while the building stays open for anyone who can get there. They are two separate decisions, made by two separate organisations, on different criteria, and announced separately.
So on a bad Greater Sudbury morning the honest answer is usually: no bus, but school is running. If that is your real question, the bus cancellation predictor weighs blowing snow and open rural roads far more heavily, because that is what actually pulls buses.
Sudbury transportation covers over 3,000 square kilometres, which is more area than some entire southern Ontario boards. Cancellations are routinely partial, because a route out toward Wanapitei can be in a different situation entirely from one downtown. The zone is the unit that matters, not the city.
Nearby
Snow squalls and drifting are intensely local in Ontario. If you are near a boundary, it is worth checking more than one:
Greater Sudbury Snow Day Questions
Will school be closed tomorrow in Greater Sudbury?
The predictor above loads Greater Sudbury's live forecast and scores it against what actually closes schools here. In Greater Sudbury the main driver is heavy snow and extreme cold together. Set the day to Tomorrow to check the next school morning.
How much snow closes schools in Greater Sudbury?
Snowfall alone has to be substantial — 20 cm or more — before closures come into play, because the city is thoroughly equipped for winter. Extreme cold is the more common trigger: at roughly −35°C to −40°C wind chill buses are pulled regardless of snow.
Are buses cancelled in Greater Sudbury when school stays open?
Frequently. Across Ontario the transportation consortium and the school board make two separate decisions, and the buses are pulled far more often than the schools close. On a bad Greater Sudbury morning the usual outcome is no bus but school still running.
What time are Greater Sudbury cancellations announced?
The consortium posts before 6:30am most mornings. Cold-day calls sometimes come earlier, because the overnight low is known well in advance in a way a snow band is not.
Is it usually cold or snow that cancels Sudbury buses?
Cold, more often than people expect. Sudbury handles heavy snow routinely, so it takes a great deal to change anything. Wind chill approaching minus 35 to minus 40 pulls buses with no snow at all, and across a northern winter that happens more often than a snowfall big enough to matter.
Does this work in centimetres?
Yes. Ontario pages default to metric, so snowfall shows in centimetres, temperature in Celsius and wind in kilometres per hour. Switch to imperial in the form if you prefer.
One Important Caveat
This is an estimate for planning, not an official notice. Only your board can close a school and only your transportation consortium can cancel buses. Always check their websites or local radio before assuming anything — and never make a travel decision based on this page instead of an Environment Canada warning.