Snow Day Calculator & Predictor 2026 – USA & Canada School Closures

Snow Day Calculator is a free tool that estimates the chance of school closing tomorrow due to winter weather. Enter your US ZIP code, Canadian postal code, or city name into the predictor above to see your snow day probability for the next 24 hours, plus a 5-day forecast and recent snow day history for your area.

Whether you call it a snow day calculator, a snow day predictor, or a school closure forecast, the goal is the same: knowing in advance whether tomorrow’s storm is likely to cancel school. Instead of guessing or refreshing the news at midnight, this tool gives you a clear percentage based on real weather data.

Disclaimer: This tool estimates the probability of a snow day based on weather forecasts and historical patterns. Your local school district makes the final decision, and conditions can change overnight.

How to Use the Snow Day Calculator

The calculator is designed to be simple. Three steps:

1. Enter your location: Type a US ZIP code (like 10001 for New York), a Canadian postal code (like M5V 2T6 for Toronto), or a city name (like Boston or Calgary).
2. Choose your district policy: If your school district closes easily at the first sign of snow, pick “Liberal.” If your district almost never closes, pick “Conservative.” Most districts are “Neutral.”
3. Click Get Snow Day Prediction: The calculator pulls live weather data and shows your snow day chance as a percentage, plus details on tomorrow’s expected snowfall, wind chill, and any weather alerts.

If you want to test different conditions yourself, for example, “what if 6 inches of snow falls during the morning commute?” switch to the Manual Calculator tab and adjust the sliders.

How the Snow Day Predictor Works

School closure decisions are not based on snowfall alone. Districts weigh several factors at once. The calculator combines seven real weather variables to estimate the chance of closure:

• Snow accumulation: Total inches expected over the next 24 hours
• Wind chill: How cold it will feel at bus stops, calculated using the standard NOAA wind chill formula
• Ice and freezing rain: Often more dangerous than snow, since untreated ice closes schools even at small accumulations
• Morning timing: Storms hitting between 5:00 AM and 9:00 AM (the “bus window”) are more likely to trigger closures than overnight storms that finish before dawn
• Wind speed: High winds combined with snow create blizzard conditions and reduce visibility for buses
• Visibility: Heavy snow that limits visibility below safe driving distances raises closure risk
• District policy: Some districts close at the first inch; others stay open through major storms

The calculator pulls hourly forecast data from Open-Meteo, a free weather data source that aggregates forecasts from national meteorological services including the National Weather Service (NWS) in the United States and Environment Canada. Each of the seven factors is weighted, then combined into a single probability percentage. Learn more about what conditions increase school closures.

What Your Snow Day Chance Percentage Means

The result is shown as a percentage from 0% to 100%. Here’s how to read it:

• 80% or higher – A snow day is very likely. Major storm conditions are forecast.
• 55% to 80% – High chance of closure. Watch for the announcement early in the morning.
• 30% to 55% – Possible snow day or delayed start. Conditions are borderline; closures are common but not guaranteed.
• 10% to 30% – Snow day unlikely, but check the morning forecast in case conditions worsen overnight.
• Below 10% – No snow day expected. School should run as scheduled.

A higher percentage means the forecast more closely matches conditions that historically lead to school closures. It’s not a guarantee, final decisions are made by superintendents based on real-time conditions on the morning of the storm.

Snow Day Calculator for the United States

The calculator works across all 50 US states using ZIP code lookup. It’s especially useful for areas where snow days are common, including the Northeast (Boston, New York, Buffalo), the Midwest (Chicago, Minneapolis, Detroit), the Mid-Atlantic (Philadelphia, Washington DC), and northern states like Maine, Vermont, and North Dakota.

The calculator also adjusts for southern states like Texas, Tennessee, and Georgia, where even half an inch of ice can shut down schools for days because road treatment infrastructure is limited. In these regions, a smaller weather event creates a higher closure probability than the same event in a snowy northern state.

Snow Day Predictor for Canada

For users in Canada, the predictor accepts standard Canadian postal codes (format: A1A 1A1) as well as city names. It works for every province and territory, including Ontario, Quebec, British Columbia, Alberta, Manitoba, Saskatchewan, the Atlantic provinces, and the territories.

Canadian school boards often have higher snowfall thresholds than American districts. Toronto, Montreal, Ottawa, and similar cities are equipped with extensive winter road maintenance and rarely close schools for snow alone, closures are more often triggered by ice storms, dangerous wind chill (below -30°C), or whiteout conditions. The calculator factors this in when estimating closure probability for Canadian locations.

Common Canadian search examples: snow day predictor Ontario, snow day predictor Toronto, snow day predictor Montreal, snow day calculator Canada. All of these work, just enter your postal code or city.

Snow Day vs. Delayed Start vs. Early Dismissal

Not every winter storm leads to a full school closure. Districts have several response options depending on storm timing and severity:

• Full snow day (school closed): Used when conditions are unsafe throughout the entire school day, or when the morning is dangerous and unlikely to improve quickly.
• Delayed start (1- or 2-hour delay): Used when the worst conditions are expected to clear before mid-morning. This gives crews time to plow roads and treat ice before buses run.
• Early dismissal: Used when a storm is forecast to arrive during the school day, allowing students to get home before conditions deteriorate.
• Remote learning day: Increasingly common since 2020, where school continues online instead of canceling entirely.

The calculator estimates the probability of closure or delay as a single percentage. A 60% result, for example, often indicates a meaningful chance of either a full closure or a delayed start.

How Much Snow Is Needed for a Snow Day?

There is no single snowfall threshold that guarantees a snow day. The amount needed varies dramatically by region:

• In the Deep South and Pacific Northwest, half an inch of snow or any ice can close schools.
• In the Mid-Atlantic and lower Midwest, 2 to 4 inches typically triggers closures.
• In the Northeast and northern Midwest, schools often stay open through 6 to 8 inches.
• In Buffalo, Syracuse, Minneapolis, and similar snow belt cities, schools may stay open through a foot of snow.
• In most of Canada, schools rarely close for snow alone, ice, wind chill, and whiteout conditions are bigger triggers.

For a more detailed regional breakdown by state and province, see our full guide on how much snow it actually takes for a snow day.

How Accurate Is the Snow Day Calculator?

The calculator provides a probability, not a guarantee. Accuracy depends on three things:

1. Weather forecast accuracy. Forecasts 12–24 hours ahead are generally reliable. Forecasts further out are less certain.
2. How well your district matches the “Neutral” default. If your specific district is unusually cautious or unusually strict, selecting “Liberal” or “Conservative” improves the estimate.
3. Local conditions the forecast can’t fully capture. Things like a single icy bridge, a power outage at the school, or a sudden temperature shift can affect closure decisions in ways the forecast doesn’t predict.

For a deeper look at prediction accuracy and how forecasts compare to actual school closures, read our analysis of how accurate snow day calculators really are.

Why the Calculator Is Better Than a Regular Weather App

A weather app tells you how much snow is forecast. The calculator translates that data into the question you actually care about: will school be closed tomorrow?

Snow accumulation alone is a poor predictor of school closures because it ignores timing, ice, wind chill, and district behavior. A 70% snow day chance in a northern Vermont town and a 70% chance in suburban Atlanta both mean the same thing, closure is likely, even though the underlying weather is completely different. That’s the value of a probability-based tool over a raw weather forecast.

Frequently Asked Questions