Snow Day Calculator
Will school be closed tomorrow? Enter your US ZIP code or Canadian city and this snow day predictor pulls a live weather forecast for your area and estimates your chance of a snow day or bus cancellation. Free, instant, no sign-up.
Reviewed for accuracy: July 2026 · Forecast data: Open-Meteo (blends NWS and Environment Canada models)
US ZIP code or city name
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In inches
In Fahrenheit
0%
Snow Day Chance
What’s Driving Your Score
Overnight & Morning Snowfall Timeline
Hourly forecast snowfall over the next 24 hours.
How This Snow Day Calculator Works for the US and Canada
This school closing predictor does not guess – it models the same variables administrators weigh before dawn, whether that is a superintendent in Ohio or a school board transportation office in Ontario. When you enter a ZIP code or city, the tool geocodes your location, pulls a live 48-hour forecast from Open-Meteo (which blends National Weather Service and Environment Canada model data), and scores your snow day probability from six weighted factors.
The single biggest driver is how much snow falls between 6 PM and 8 AM local time – snow during the school day rarely triggers a closure, but snow that lands overnight forces a decision before buses roll. The model then layers on timing (snow falling between 4 and 8 AM is the plow crew’s nightmare, because there is no window to clear roads), precipitation type (freezing rain and ice storms close schools at a fraction of the accumulation snow requires), dangerous cold (wind-chill closures and Canadian-style bus cancellations kick in during extreme cold snaps), sustained winds above 25 mph / 40 km/h (blizzard and visibility risk), and your region’s snow tolerance.
That last factor matters more than most people realize. Two inches (5 cm) of snow can shut down Atlanta for days, while Ottawa or Buffalo would barely post a two-hour delay. The calculator auto-detects a regional tolerance from your location – Canadian locations default to high tolerance with extreme-cold logic, and US locations are inferred from latitude – or you can override it manually. Finally, a school-type modifier adjusts the score: rural districts with long, untreated bus routes close (or cancel buses) more readily, while boarding schools, where every student already lives on campus, almost never do.
The output is capped at 99%. No snow day predictor – including this one – can promise a cancellation. The final call always belongs to your local school district or school board.
How Much Snow Does It Take to Cancel School?
There is no universal threshold – the amount of snow needed to cancel school depends almost entirely on how routine snow is in your region and how much snow-clearing equipment local authorities own. These are the typical closure thresholds across North America, with a few international benchmarks for comparison:
| Region | Typical Closure Threshold | Why |
|---|---|---|
| US South (GA, TX, NC, TN) | 1–2 in (2.5–5 cm), or any ice | Few plows, little salt, drivers unaccustomed to snow |
| US Mid-Atlantic (VA, MD, NJ) | 3–4 in (8–10 cm) | Moderate equipment; ice and timing tip the decision |
| US Midwest (OH, IN, IL, MO) | 5–6 in (13–15 cm) | Well-equipped, but wind chill closures are common |
| New England / Great Lakes | 6–10+ in (15–25+ cm) | Heavy plow fleets and generational snow experience |
| BC Lower Mainland (Vancouver) | 5–10 cm (2–4 in) | Rare snow, hilly terrain, minimal plow coverage |
| Canada (ON, QC, Prairies, Atlantic) | 15–25+ cm (6–10+ in); buses cancel sooner | Schools often stay open while buses are cancelled; extreme cold near −35°C wind chill triggers its own cancellations |
What Actually Goes Into a School Closing Decision
Administrators do not just look at a snowfall total. The decision usually comes together between 4:00 and 5:30 AM, after transportation staff physically drive the bus routes. Here is what tips the scale:
- Timing beats totals. Four inches that finish falling by midnight can be plowed before dawn. Two inches falling at 6 AM cannot – which is why the chance of school being canceled spikes when snow is forecast between 4 and 8 AM.
- Road treatment status. If overnight temperatures were too cold for salt to work, or rain washed the brine away, untreated roads make even light snow dangerous.
- Bus routes are the bottleneck. A district or school board closes – or cancels buses – when its most rural, hilliest route is unsafe, not when the main road by the school is clear. In much of Ontario, Quebec, and Atlantic Canada, bus cancellations are announced while school buildings technically stay open.
- Extreme cold policies. Many Canadian boards and US Midwest districts cancel automatically when wind chills reach roughly −30°C to −40°C (−22°F to −40°F), even with no fresh snow, because children waiting at bus stops risk frostbite within minutes.
- Ice changes everything. A quarter inch (5 mm) of freezing rain will close districts that routinely handle six inches of snow – it is the single most common closure trigger in the US South.
Snow Day Calculator FAQ
Snow day calculators are probability estimates, not guarantees – a well-built one is typically directionally right when forecasts are stable, but accuracy drops when storms shift track or timing. This tool uses live forecast data and the same factors districts weigh (overnight accumulation, snow timing, ice, wind chill, and regional tolerance), so treat a high score as a strong signal, not a promise. The final decision always rests with your school district or school board.
Yes – select Canada and enter your city (Toronto, Ottawa, Calgary, Halifax, or any Canadian town) and the tool pulls a live local forecast and applies Canadian closure logic: high snow tolerance, extreme-cold bus cancellation thresholds, and results displayed in centimetres and Celsius. City names work best; if a postal code is not recognized, enter your nearest town instead.
Most US and Canadian districts announce closures or bus cancellations between 5:00 and 6:30 AM on the day of the storm, after transportation staff drive the routes at dawn. If the forecast is severe and certain, many districts announce the evening before, typically between 8:00 and 10:00 PM. Check your district or school board website, app, or local news alerts for the official call.
Yes – ice closes schools at far lower accumulations than snow. As little as a tenth to a quarter inch (2-5 mm) of freezing rain can make roads and sidewalks impassable, snap power lines, and stop buses, so districts that shrug off six inches of snow will close for a minor ice storm. This calculator sharply increases the probability whenever freezing rain appears in your forecast.
In Southern US states, 1 to 2 inches of snow – or any ice at all – is usually enough to cancel school, because plows and salt supplies are scarce. In New England and the Great Lakes region, districts typically need 6 to 10 or more inches before closing. Mid-Atlantic districts fall in between at roughly 3 to 4 inches, and most of Canada needs 15 to 25 centimetres, though buses are often cancelled well before schools close.
In much of Canada – especially Ontario, Quebec, and Atlantic Canada – school boards and bus consortia make separate decisions: buses are cancelled when rural roads or visibility are unsafe, while school buildings remain open for families who can drive or walk. In practice, a bus cancellation functions as a snow day for most rural students. Extreme cold is the other uniquely Canadian trigger: many boards cancel buses automatically when wind chill reaches about minus 35 degrees Celsius.
In many districts, yes – remote learning days now substitute for some or all traditional snow days, especially in US states that cap forgiven closure days and in school boards that adopted e-learning after 2020. However, plenty of districts have deliberately kept true snow days, citing childhood tradition and unequal home internet access. Whether a closure means a day off or a laptop day depends entirely on your local district or school board policy.
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Disclaimer: This snow day probability tool provides probabilistic estimates for planning and entertainment purposes only. Official closure, delay, and bus cancellation decisions rest solely with individual school districts and school boards – always check your official local announcements. Forecast data courtesy of Open-Meteo; see also weather.gov (US) and Environment Canada for official warnings.