Snow Day Calculator
Predict tomorrow's school cancellation odds.
What is snow day calculator?
The Snow Day Calculator is a fast, transparent way to estimate the odds that school will be cancelled tomorrow. You enter the forecast — snowfall, temp, wind, ice, region, school type, day, plus a luck slider — and the page returns a 0–99 % probability with a plain-language verdict and a per-input breakdown so you can see exactly what’s driving the call.
It’s not a weather feed. There’s no API, no signup, no tracking — everything runs in your browser. That makes it easy to play with what-ifs (“what if the storm only drops 3 inches?”, “what if it shifts to ice?”) and to see how each factor moves the number.
The real cancellation call belongs to your school district. This calculator gives you a half-serious gut-check before you go to bed; the official word always comes from the superintendent in the morning.
When to use a snow day calculator
- Late-night homework triage — Students checking before bed whether to charge through one more chapter or punt it. The verdict line gives a quick gut-check, and the breakdown shows whether the call hinges on snowfall, temperature, or just optimism.
- Morning planning for parents — Parents sketching out the next day — daycare backup, work-from-home calls, school dropoff timing. A 70%+ reading is a cue to line up a contingency the night before instead of scrambling at 6 AM.
- Teacher prep and sub coverage — Teachers and subs use it as a half-serious nudge for whether to grade the stack tonight or punt to a possible snow morning. The factor breakdown is also a fun classroom prompt about how cancellation decisions get made.
How to use the Snow Day Calculator
- Enter the forecast — Type in the predicted snowfall, low temperature, and wind speed for the storm you're tracking.
- Pick storm timing and ice risk — Overnight storms cancel more often than evening ones. Tick the ice/sleet box if a wintry mix is in the forecast — even a half-inch of ice can do what 12 inches of snow can't.
- Set school type, region, and day — Public K-12 is the baseline. Colleges cancel less; homeschool overrides everything. Region adjusts how heavily snowfall is weighted — Southern US cancels at much lighter totals than the Mountain West.
- Read the verdict and breakdown — The big number is your odds. Open the breakdown to see which inputs are pushing the result up or down — handy for a what-if ("what if the storm shifts north and we only get 3 inches?").
Worked examples
Light flurries, mild night, public K-12
Input: 1 inch snowfall, 30°F low, 8 mph wind, daytime storm, public K-12, Wednesday, Northern US, luck 5
Output: ~17% — School's on. Pack the lunch.A dusting on a mid-week morning rarely cancels in the snow belt.
Half-foot overnight in the South
Input: 6 inches snowfall, 22°F low, 15 mph wind, overnight storm, public K-12, Friday, Southern US, luck 6
Output: ~85% — Snow day incoming. Sleep in.Southern districts cancel earlier and more often. Friday and overnight timing both add a few extra points.
Big storm, college campus
Input: 10 inches snowfall, 18°F low, 20 mph wind, all-day storm, college, Tuesday, Mid-Atlantic, luck 7
Output: ~70% — Likely snow day. Charge the sled.Same storm at a public K-12 would read closer to 95% — colleges cancel less readily.