Snow Day Calculator
Free snow day calculator for planning: snow inches, overnight low °F, wind gusts, freezing rain flag, sensitivity slider, 0–100 illustrative index, and mortgage-style scenario rows—plus a guide. Not official school closures.

Important: School and employer closures are decided by officials using policies you cannot see from a browser form. This page is an illustrative weather-impact index for planning and classroom discussions—not an official forecast, not a district decision, and not a replacement for NOAA / NWS alerts or your local transportation department.
Summary: Enter rough forecast snow, an overnight low temperature (°F), wind gusts, whether freezing rain / sleet is in play, and a playful “how cautious institutions tend to be here” slider. The tool outputs a 0–100 snow-day vibe index plus scenario rows—same spirit as the mortgage calculator’s stress checks—so you can see sensitivity before you trust vibes alone.
What this toy does — and does not (tap to expand)
- Does: combines your inputs with a transparent scoring recipe, normalizes to 0–100, assigns a plain-English band, and shows small counterfactual rows (more snow, colder low, higher wind).
- Does not: read bus garage policies, road treatment routes, union contracts, elevation microclimates, or tomorrow’s actual superintendent mood.
Snow day calculator (illustrative index)
Teachers sometimes use “snow day math” as a relatable intro to functions and sensitivity analysis. Parents sometimes use it to decide whether to charge the laptop and find the sled. Meteorologists use better tools. Everyone wins if we keep the roles straight.
Assumptions & methodology (short)
- Snow points: forecast inches × 6.5 (capped internally before final clamp).
- Cold stickiness: max(0, 32 − °F) × 1.2 (freezing and below nudges totals).
- Wind: min(18, gusts ÷ 4).
- Freezing rain / sleet flag: +28 points (buses and power lines care a lot).
- Institution sensitivity (1–5): multiplies the running sum by (0.92 + n×0.04)—roughly “stricter contexts react earlier.”
- Final score is clamped to 0–100.