Southwestern Ontario · In centimetres
Snow Day Predictor London
Will school be closed tomorrow?
Loading London's live forecast now. Tuned for what actually closes schools here — Lake Huron snow squalls.
London Closure Chance
In Ontario a bus cancellation is the likelier outcome — check the bus cancellation predictor for that.
What Closes Schools in London
London is a squall city, which surprises people who think of the snowbelt as a Georgian Bay phenomenon. Cold air crossing Lake Huron produces bands that run inland and park over southwestern Ontario, and London sits squarely in their path.
Huron squalls behave the same way Georgian Bay squalls do: intense, narrow and highly localised. London can record 30 cm from a band while Woodstock, an hour east, records nothing. The 401 and 402 corridors west of the city close to whiteouts most winters, and those are the roads a great many rural routes depend on.
What a Bad Morning Actually Looks Like
A bad London morning arrives off Lake Huron and stays. A band sets up over the city and does not move for six hours, the 401 and 402 close to whiteouts west of town, and rural Middlesex routes are gone before dawn while the forecast for the region as a whole said something quite modest.
How Much Snow It Takes Here
The area is used to squalls and equipped for them, so schools hold open through amounts that would close other boards. Bus cancellations are the usual outcome, typically from about 15 cm with wind, and often applied to rural zones only.
London squalls make timing unusually decisive: a band that parks over the city from 3am to 8am produces a completely different morning from the same total falling in the afternoon. 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 London, 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 London 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.
Thames Valley routes run a long way out into Middlesex and beyond, and those are the runs the squalls take. City routes are cancelled far less often than the county ones, so a cancellation here usually needs reading carefully.
Nearby
Snow squalls and drifting are intensely local in Ontario. If you are near a boundary, it is worth checking more than one:
London Snow Day Questions
Will school be closed tomorrow in London?
The predictor above loads London's live forecast and scores it against what actually closes schools here. In London the main driver is Lake Huron snow squalls. Set the day to Tomorrow to check the next school morning.
How much snow closes schools in London?
The area is used to squalls and equipped for them, so schools hold open through amounts that would close other boards. Bus cancellations are the usual outcome, typically from about 15 cm with wind, and often applied to rural zones only.
Are buses cancelled in London 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 London morning the usual outcome is no bus but school still running.
What time are London Ontario cancellations announced?
Announcements typically appear between 5:30am and 6:30am. Squall mornings often run to the later end, because the band position at 5am is what the decision rests on.
Is London in the Ontario snowbelt?
Yes, though it is not usually thought of that way. Cold air crossing Lake Huron produces squall bands that run inland and settle over southwestern Ontario, and London sits directly in their path. It can record 30 cm from a band while Woodstock, an hour east, records nothing at all.
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.