How SnowDayOdds works

1. Find your location

You search where you live. SnowDayOdds.com finds the local weather forecast for your area.

Geocoding is the separate step that turns a place name or ZIP into a location for the weather lookup. It does not supply the weather or determine a school's attendance boundary. Check the displayed location before using the result.

2. Check for winter weather

We use official National Weather Service forecast information as weather input. Our own model evaluates snow, ice, sleet, freezing rain, and other winter weather that could affect the school day.

The National Weather Service provides the weather information, not these school-impact probabilities. Automated checks look for usable weather data covering the forecast window and valid model output before publication. A missing or unusable input is not treated as evidence of clear weather.

3. Timing matters

Snow overnight or during the morning commute matters differently than snow arriving after school begins. We also consider temperature, ice, snow intensity, and wind when it makes winter conditions worse.

Read the Snow-day guide for how timing, roads, transportation and local weather differences can affect school-day planning.

4. Calculate the odds

Our meteorologist-designed model independently estimates four local school-day outcomes: Snow Day, Delayed Start, Early Dismissal, and Normal School. These are not snowfall chances, percentages of nearby schools, or official district decisions.

• Snow Day: a full-day closure due to winter weather.
• Delayed Start: school begins later than its normal schedule.
• Early Dismissal: school ends earlier than its normal schedule.
• Normal School: no modeled winter-weather schedule disruption.

The four displayed percentages total 100% for each school date. Compare them as the model's distribution across those outcomes, not four independent weather forecasts. The highest percentage identifies the favored outcome; it does not make the other outcomes impossible. A school that delays and later closes can also have a more complicated real-world schedule than these four simple categories describe.

The same normalized weather inputs and model version produce the same odds for the same forecast window. New official weather information may change later forecasts; a new check does not necessarily change the percentages.

When the model finds no qualifying winter-weather disruption signal for that forecast window, it can show 100% Normal School. This is not confirmation that your school is officially open.

Publication and later update checks

The public percentages come from a stored, published forecast for the stated school date, not a new calculation on every page view. A later check for weather updates is separate from publishing a new forecast. If the relevant weather inputs and model version are unchanged, the existing publication can remain in use while it is valid. Even changed inputs do not guarantee different rounded percentages.

The displayed update information helps you judge timing; it does not mean a meteorologist manually approved each result. Forecast checks and publication are automated. A forecast may temporarily be unavailable while a calculation is in progress, when usable weather data cannot be obtained, or when there is no valid publication for the requested school-day window. Unavailable does not mean 0% Snow Day or 100% Normal School.

Read confidence separately from the odds

Confidence reflects data completeness, agreement across forecast points, time until the school day, and weather-data freshness. It is not the probability of a closure and not a measured success rate. High confidence does not turn a local estimate into an official school decision. See Accuracy for the current calibration and validation limits.

What a local forecast cannot know

The weather-based estimate does not inspect a particular bus route, school parking lot or sidewalk. It does not know a district's staffing, transportation readiness or final deliberations. Selecting a town or ZIP does not select an individual school, and the result is not a verified closure notice. Your school's official announcement is the source for its actual schedule.

Common questions

Does a 60% Snow Day forecast mean 60% of schools will close? No. It is the model's estimate for the Snow Day outcome in the stated area and window, not a count or survey of schools.

Why did I check again and see the same odds? A new visit or scheduled check is not itself new weather information. The relevant inputs may be unchanged, or a change may be too small to change the displayed percentages.

Can nearby places show different odds? Yes. Local weather inputs can differ. Compare the same school date and read each explanation; the guide gives examples of why a regional snow total can miss local impacts.

Should I follow these odds instead of my school's notice? No. Use the forecast to plan for possibilities, then follow your school's confirmed instructions.