CalcKitSnow Day Calculator
Tomorrow’s forecast
This is a fun estimate for entertainment only — it is not an official school closure announcement. Always check your school district’s website, phone line or local news for the real decision.
Estimate only — not an official closure announcement.
Example: 8 inches of snow, 28°F, falling overnight → 85% chance of a snow day (very likely).
Behind the numbers
How the snow day odds are estimated
Schools usually close when roads are unsafe before the morning commute, so the estimate scores the three things that matter most: how much snow falls, how cold it stays, and when it falls. Snowfall carries the most weight — up to 72 points — because a foot of snow closes roads almost anywhere, while an inch rarely does.
For the example: 8 inches gives 72 snowfall points, 28°F gives 8 temperature points, and overnight timing gives 5 points — 85 points in total, an 85% chance. The result is capped at 97%, because even a blizzard is never a sure thing.
A few comparisons
What different forecasts mean
Same scoring, different weather. Overnight snow at or below freezing is what closes schools; light snow during the day usually does not.
| Forecast | Score | Chance |
|---|---|---|
| 12 in, 25°F, overnight | 85 of 97 | 85% |
| 8 in, 28°F, overnight | 85 of 97 | 85% |
| 6 in, 20°F, early morning | 77 of 97 | 77% |
| 3 in, 30°F, during the day | 35 of 97 | 35% |
| 1 in, 34°F, during the day | 13 of 97 | 13% |
Read the forecast like a snow day hunter.
Overnight snow matters most: plows have all night to work, but if it is still falling at 5 a.m., buses usually cannot run on time.
Temperature near freezing is the wildcard. Snow at 31°F melts and refreezes into ice, which can close schools with only a couple of inches on the ground.
Wind and ice warnings matter more than inches alone. A district can close for 3 inches plus ice while staying open for 6 inches of light, dry snow.
Check the official source before you celebrate: your district’s website, its phone line or local TV. This calculator is for fun — it never closes a school.
Good to know
Your snow day questions, answered.
Is this an official school closure announcement?
No — this calculator is an estimate for entertainment only. Only your school district can close school. Always check your district’s official website, phone line or local news for the real decision.
How much snow does it take to close school?
It depends on where you live. In many US districts, 4–6 inches overnight is often enough, while 1–2 inches rarely closes anything. Districts that see little snow may close for less, and districts used to heavy snow may stay open with more.
Why does the timing of the snow matter?
Schools decide early in the morning, so snow that falls overnight hits the decision window. Snow that starts after school begins usually means an early dismissal, not a full closure, and evening snow is judged the next morning.
Why is the chance capped at 97%?
Because no forecast is a sure thing. Even with a foot of snow overnight, a district with a strong plow fleet and a late start option can still open. The cap keeps the estimate honest.