From weather forecast to snow day probability
When you enter your zip code and school type, the snow day calculator pulls the latest weather forecast data from the National Weather Service (for US locations) or Environment Canada (for Canadian locations). It then analyzes multiple weather variables that affect school closure decisions and combines them with regional closure patterns to produce a single snow day probability percentage.
Unlike a basic weather forecast that just tells you how much snow to expect, a snow day calculator interprets what that weather means for your school. Two inches of snow in Atlanta has a very different impact than two inches in Chicago — and our model accounts for those regional differences automatically.
The prediction updates every time you check, so you always get results based on the most current forecast data available. For the most accurate snow day prediction, check the calculator after 6 PM the evening before a potential snow day, when weather models are at their most reliable for the next-day forecast.
What the calculator analyzes
Snowfall accumulation
The calculator checks how many inches of snow are expected in your area over the next 24 hours. Heavy snowfall is the single biggest driver of school closures, but the threshold varies — 2 inches may close schools in the South while 8 inches barely registers in Minnesota.
Ice and freezing rain
Ice accumulation is often more dangerous than snow. Even a thin glaze of ice can make roads impassable and bus routes unsafe. The calculator weights ice events heavily because they trigger closures at lower precipitation totals than snow alone.
Wind chill and temperature
Extreme cold can cancel school even without snow. Many districts have wind chill policies — if the wind chill drops below -25°F to -35°F depending on the region, schools close to protect students waiting at bus stops and walking to school.
Storm timing
A storm that drops 4 inches overnight is far more disruptive than one that starts at noon. The calculator evaluates when snowfall is expected relative to the morning commute window. Early-morning storms that coincide with bus schedules are much more likely to trigger closures.
Road conditions and bus routes
The calculator considers how quickly roads in your area are typically cleared and whether your district relies heavily on bus transportation. Rural districts with long, hilly bus routes close more readily than urban districts where students walk or take public transit.
School type and regional patterns
Public schools, private schools, and colleges have different closure thresholds. The calculator adjusts based on your school type and the historical closure patterns for your region — some districts are cautious and close proactively, while others try to stay open unless conditions are severe.
How accurate is the snow day predictor?
The accuracy of any snow day prediction depends on the quality of the underlying weather forecast. Weather models are most accurate within a 12 to 24 hour window, which is why evening-before predictions tend to be the most reliable. A prediction made three days out will be less precise because storm tracks and snowfall totals can still shift significantly.
Our calculator also shows you the key factors driving the prediction — snowfall totals, ice risk, wind chill, and timing — so you can make your own judgment alongside the probability percentage. We always recommend confirming with your school district's official announcements, which are typically made between 5 and 6 AM the morning of the event.
Check your snow day chance
Enter your zip code and school type to get a real-time school closure prediction.
Open the snow day calculator