How we measure accuracy
Every morning at 06:10 UTC we freeze each provider's forecast for the next 5 days. The next day we compare it with real observations (METAR from the reference airport, public domain). Metrics follow WMO/TD 1023: mean absolute error and bias of daily high/low, share of days within ±2 °C, contingency table for rain yes/no (≥ 0.1 mm or reported phenomenon), wind error. The baseline is persistence ("tomorrow like today"). 30-day scores need 30 days of data; rain scores need 90. No AI touches any value.
Cities
- Forecast accuracy for Toronto
- Forecast accuracy for Montréal
- Forecast accuracy for Calgary
- Forecast accuracy for Ottawa
- Forecast accuracy for Edmonton
- Forecast accuracy for Winnipeg
- Forecast accuracy for Mississauga
- Forecast accuracy for Vancouver
- Forecast accuracy for Brampton
- Forecast accuracy for Hamilton
- Forecast accuracy for Surrey
- Forecast accuracy for Québec
- Forecast accuracy for Halifax
- Forecast accuracy for Laval
- Forecast accuracy for London
- Forecast accuracy for Etobicoke
- Forecast accuracy for Markham
- Forecast accuracy for Vaughan
- Forecast accuracy for Gatineau
- Forecast accuracy for Victoria