How accurate is snow day calculator?

A snow day calculator estimates the likelihood that a school or workplace will close due to snow by using weather forecast data, historical closure patterns, temperature, snowfall amounts, and sometimes local rules.

Accuracy:
• Better than guessing, because it uses real forecast and historical data.
• Not perfect — forecasts change, and closures depend on local decisions (road conditions, staffing, safety policies) that the model can’t fully predict.
• Most reliable 1–3 days ahead; accuracy drops for longer-range forecasts.

In short: A snow day calculator gives a useful probability based on weather data, but it should be taken as an estimate, not a guarantee, because real decisions involve human judgment and changing conditions.