ChanceOfSnowDay is a weather-based planning tool for school closures and delayed openings. It combines live forecast signals such as snowfall timing, freezing precipitation, extreme cold, wind, visibility, and—where available in the United States—official National Weather Service winter alerts.
What the calculator does
The calculator estimates three separate outcomes for the forecast location: school closed, delayed opening, and normal schedule. It also shows the weather factors behind the estimate and a five-day planning outlook.
What the calculator does not know
A weather model cannot know every local operating factor. School districts, boards, transportation authorities, colleges, and campuses may consider road treatment, bus routes, staffing, facilities, power, policy, and other local conditions that are not part of a general weather forecast. Official notices always take priority over this website.
Local context and sources
Selected local prediction pages include reviewed guidance from official school-board, district, transportation, government, or campus sources. We do not invent historical closure rates or assume one district’s policy applies everywhere.
How we evaluate the model
Visitor-requested predictions can be stored by location, forecast date, mode, and model version. When an outcome can be paired with an official source, it may be used for internal calibration. We do not publish a model accuracy percentage until the verified dataset is large and diverse enough for a separate review.
Start with the Snow Day Calculator, compare selected markets on the Snow Day Risk Map, or read How Schools Decide Snow Days for the local decision factors a weather model cannot fully observe.