FAQ

Our predictor achieves approximately 85–90% accuracy for major snow events (15 cm or more) and 70–75% for marginal events (5–10 cm). For extreme cold events (wind chill -35°C or colder), accuracy is 80–88%. Accuracy is highest when checked at 5 AM on the morning of a storm, after overnight forecast updates. See our How It Works page for a full breakdown by event type.

All 10 provinces: Ontario, Quebec, British Columbia, Alberta, Nova Scotia, New Brunswick, Manitoba, Saskatchewan, Newfoundland and Labrador, and Prince Edward Island. See each province’s dedicated page for the specific school boards covered in that province.

Completely free — no account, no email address, no subscription. Enter your city and get your answer. snowpredictor.ca will always be free for Canadian parents and students.

Weather data updates every hour for all Canadian locations. During active weather events, updates may be more frequent as Environment Canada pushes new model runs. For the most accurate prediction, check at 9 PM the night before for a preliminary read and again at 5 AM on the morning of the storm for the final pre-announcement assessment.

AccuWeather provides weather forecast data. snowpredictor.ca interprets weather data through a school closure algorithm specifically calibrated for Canadian school boards. AccuWeather tells you 20 cm is coming — we tell you there is a 78% chance school will be cancelled in Barrie because of it. Both tools serve different purposes and ideally you would use both. Read our full comparison here.

A bus cancellation means school buses are not running but schools remain physically open. Students who can travel independently are expected to attend; students who normally take buses are excused from attendance. A snow day means the school itself is closed and everyone stays home. Our predictor is calibrated for full school closures, not transportation-only cancellations.

The Director of Education or a designated senior administrator at the school board level makes the closure decision — not individual principals. One board decision closes all schools in the district simultaneously, affecting every student in the jurisdiction. See our guide on how Canadian schools decide on snow days.

Most Canadian school boards announce by 6:00–6:30 AM through their website, automated notification systems (SchoolMessenger), and local radio. Some boards issue advance notices by 10:00 PM the night before when conditions look severe. Check your province page for board-specific announcement times and channels.

Our algorithm is calibrated for public school boards. Private schools make independent decisions that can differ significantly from public board closures under identical weather conditions. Use our score as a general winter severity indicator for private school closures rather than a precise prediction.

Our algorithm is built for K–12 schools. Universities and colleges typically remain open under conditions that close K–12 schools and make fully independent decisions. Treat our score as a general winter severity indicator for post-secondary institutions.

The most common reasons: the weather forecast changed significantly between when you checked and when the board decided (always recheck at 5 AM); the storm was a highly localised lake-effect event that regional models underestimated (common in Barrie and Kingston); or the board made an unusual decision that deviated from its historical pattern. We log prediction misses and use them to improve calibration each season.

Predictions are most reliable within 24 hours. We display data up to 48 hours ahead but weather model accuracy drops significantly beyond one day. Always recheck at 5 AM on the morning of a storm for the most current and accurate assessment before your board announces.

Snowpredictor.ca is fully mobile-optimised — no app download needed. On iPhone: tap the Share button → Add to Home Screen. On Android: tap the three-dot menu → Add to Home Screen. This creates a home screen icon for instant access, just like a native app.

A 0% or near-zero probability means our algorithm sees no significant weather factors that would trigger a school closure — school is almost certainly open. This typically appears on clear, cold winter days with no precipitation in the forecast.

Our maximum output of 98% represents the highest confidence we express — an event where historical patterns strongly indicate closure and all weather factors point decisively toward a school day cancellation. It does not mean school is guaranteed to close; it means we assess the probability as extremely high based on the available data.