Snow Day Calculator
A just-for-fun estimate of the chance school is cancelled tomorrow, from the forecast snowfall and temperature. Calculates instantly in your browser.
Chance of a snow day
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Show the math
Snowfall drives the chance on a saturating curve:
chance ≈ 100 × (1 − e−snow / 4), adjusted for temperature
About 4 inches gives a coin-flip and 12 inches is near-certain. Temperatures below freezing add a little for icy roads; above freezing subtracts as snow melts. This is just for fun, always check your district's official channels. All math runs locally in your browser.
What this does
A snow day calculator gives a light-hearted estimate of the chance that school is cancelled tomorrow, based on the forecast snowfall and temperature. It is a novelty — not a real prediction of any school district’s decision.
How to use it
- Enter the forecast snowfall in inches.
- Enter the expected temperature in °F.
- Read the estimated chance and verdict.
- Cross your fingers and check your district’s official channels.
How it works
Snowfall is the dominant factor on a saturating curve — about 4 in gives a coin-flip and 12 in is near-certain. Temperatures below freezing add a little for icy roads, while above-freezing temperatures subtract because snow melts.
chance ≈ 100 × (1 − e^(−snow / 4)), adjusted for temperature
Understanding your result
A higher percentage means a better chance of a day off, but it is only a bit of fun — real closures depend on road crews, local policy, and timing that no formula can capture. Always rely on your school or district’s official announcement.
Example
A 6 in forecast at 25°F comes out around 80% — "very likely".
Sources & methodology
Last updated .
Frequently asked questions
Is this a real prediction?
No — it is purely for fun. Actual snow days depend on road conditions, district policy, the timing of the storm, and local judgement, none of which a simple formula can know.
What raises the chance most?
Heavy snowfall has the biggest effect, with cold temperatures adding a little because roads stay icy. Warm forecasts lower the chance because snow melts.
Is anything stored?
No. Everything is calculated locally in your browser.
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