Why Hamilton is different
Almost everywhere else in Ontario a bus cancellation leaves schools open. Hamilton’s public board ties the two together: when HWDSB cancels busing for weather, its schools close too. The Catholic board decides separately. So on this page the card shows three numbers from one forecast: the chance buses are cancelled, which is also the chance HWDSB closes, and the smaller chance HWCDSB closes its schools as well.
How to use it for Hamilton
The calculator opens on Hamilton in metric, with the climate of the Hamilton airport station on the Mountain. Type in the overnight snowfall your forecast gives, whether it ends before the buses run, and any freezing rain, then the temperature and wind expected around 7 a.m.
Hamilton averages about 156 cm of snow a year, and about 15 cm falls in a day roughly once a winter. With 10 cm overnight the calculator gives about 50%; with 15 cm, about 70%. Freezing rain is Hamilton’s classic trigger: the escarpment roads between the lower city and the Mountain glaze quickly, and the February 2025 closure followed a freezing rain advisory, not deep snow. Pick the ice option honestly, even for a light glaze.
The airport station sits above the escarpment and gets more snow than the lower city, so if you live below the Mountain, the real chance may be a little lower.
After you check
HWDSB emails families by 6 a.m. and HWCDSB posts by 6:30 a.m. If HWDSB announces a bus cancellation for weather, public schools are closed; for Catholic schools, read the board’s message.
Hamilton: the numbers the calculator uses
| Snow in an average year | 156 cm (62 in) |
|---|---|
| One-day snowfall reached about once a winter (the snow tolerance) | 15 cm (6 in) |
| Average winter low, December to February | −8 °C (18 °F) |
| Climate station | Hamilton A, ECCC Canadian Climate Normals 1981–2010 |
| Headline outcome | Buses cancelled; HWDSB (public) schools close too, HWCDSB (Catholic) schools may stay open |
| Cold rule | No published rule found; the calculator estimates about −30 °C (−25 °F) wind chill. |
| Official call | HWDSB: inclement weather: Hamilton is different. The public board (HWDSB) closes its schools whenever buses are cancelled for severe weather, and emails families by 6 a.m. Catholic (HWCDSB) schools may stay open when buses are cancelled; it announces by 6:30 a.m. |