Snow day questions

It is built around public school districts (NCES data). Many private schools follow the local public district's decision, so the district chance is a good guide. Colleges close less often than K-12 schools for the same weather.

District boundaries don't follow ZIP codes, so one ZIP can overlap several districts. Pick yours from the list; the first one covers the largest part of the ZIP.

Because the forecast changes. The National Weather Service updates its forecast through the night, and we recalculate every hour, so a storm that shifts or slows shows up in the next update.

Not yet. It uses the National Weather Service forecast grid for the lower 48 states and DC. Alaska is planned.

It depends on where you live and when it falls. Six inches overnight closes schools in most of the country, but areas that average many snowy days a year (Buffalo, Syracuse, the Upper Midwest) often stay open or delay. Snow that ends before about 4 AM gives crews time to clear roads; snow at bus time is what closes schools.

Yes, for snow, ice, extreme cold, and sometimes flooding or power outages. Each district decides for itself, usually early in the morning after checking roads and the forecast.

Often. Most states set a minimum number of school days or hours, so districts build extra days into the calendar or add days later. Some states and districts allow remote-learning days instead. Check your district's calendar for its plan.

We don't publish an accuracy figure yet, because there is no honest way to measure it without real outcomes. We collect parent reports this winter and will publish how often each chance level matched what districts did.

Usually early in the morning, after district staff check the roads, and sometimes the evening before when a major storm is certain. The calculator updates every hour overnight, so check again in the morning.

It is free and needs no account. You can add it to your phone's home screen so it opens like an app; see the App page.