A free cold day and ice day calculator: the chance bitter wind chill or freezing rain closes school on the next school morning
An estimate from the forecast, not a promise.
Looks like a regular school day for cold and ice. Check again if the forecast changes.
🧪 Test weather, not the real forecast
Snow is in the forecast too (0.0 in). This page doesn’t score snow; the Snow Day Calculator scores snow, ice, cold and wind together.
In much of Canada, school buses can be cancelled while schools stay open. This is a weather estimate, not an official bus cancellation; check your school board or bus service.
Opens a web search in a new tab. Only your school district can say for sure.
Days 3–5 are an early outlook and may change. School holidays aren’t known.
Coldest bus-time reading: —
No freezing rain expected overnight
Top: air temperature. Bottom: wind chill. 🧊 = freezing rain in the hour before.
Overnight window: 6 pm – 8 am before school. Bus time: the 6, 7 and 8 am readings.
A cold day is a school closure or delay called because of extreme cold rather than snow: students waiting at bus stops or walking to school face frostbite when the wind chill is low, and buses can fail to start. An ice day is a closure for freezing rain, which glazes roads and sidewalks with ice even when no snow falls. This cold day calculator for school (also a cold day predictor) estimates the chance of either on the next school morning, for towns in the US and Canada. It scores the wind chill at bus time, the overnight low and hours of freezing rain. It’s an estimate, not an announcement: only your school district or school board decides.
Method
The estimate comes from the forecast and a short, published set of rules.
Using the searched place’s local time: before 6 am on a weekday, that’s today. Otherwise it’s the next weekday, so Fridays and weekends look ahead to Monday.
Wind chill uses the 6, 7 and 8 am readings, when students wait for buses or walk to school. The overnight low and freezing rain use the hourly forecast from 6 pm to 8 am.
A starting point of 2, plus points for each factor below. Snow isn’t scored here; the Snow Day Calculator does that. Canadian places see °C and km/h; the points are the same.
The total points become the percentage, rounded and kept between 1% and 99%. 60% or higher reads Likely, 30–59% Maybe, and under 30% No Chance.
Coldest of the 6, 7 and 8 am readings
| −10°F (−23°C) | 0 |
|---|---|
| −18°F (−28°C) | +28 |
| −40°F (−40°C) | +58 |
| −54°F (−48°C) or colder | +70 |
Values in between get points in between. The steps follow Environment Canada’s frostbite risk levels: “high risk” starts at −28°C and “very high risk” at −40°.
Lowest temperature, 6 pm – 8 am
| −20°F (−29°C) or colder | +5 |
|---|---|
| −30°F (−34°C) or colder | +10 |
A small factor for buses that may not start and heating trouble in deep cold.
Hours of freezing rain or drizzle overnight
| 1–2 hours | +30 |
|---|---|
| 3–5 hours | +50 |
| 6 hours or more | +65 |
The same points as the snow day calculator, so a night of ice alone gives the same estimate on both.
The “feels like” temperature on skin
Wind chill (°F) = 35.74 + 0.6215T − 35.75(V0.16) + 0.4275T(V0.16)
The formula from the National Weather Service wind chill chart. T is the air temperature in °F and V the wind speed in mph, measured 33 feet (10 m) up. It applies at 50°F or colder with wind above 3 mph; otherwise the air temperature is used.
These point values are first estimates, not yet measured against real closings, so the result’s accuracy is unknown. The page has no questions about your district, and its scale is set for places used to cold: schools in milder regions, such as the South and the mid-Atlantic, may close or delay at much less extreme cold than it assumes. For your own result’s breakdown, open More weather details → Why this number?
Thresholds
There’s no national rule in the US or Canada. Each school district or school board sets its own practice, and many decide case by case from the morning forecast, so the same cold can close schools in one region and not in another.
In this calculator, a wind chill of about −18°F (−28°C) at bus time reaches Maybe, and −40° reaches Likely, when nothing else adds points. Only your district or school board decides.
Ice
An ice day is a closure for freezing rain or freezing drizzle: rain that falls as liquid and freezes when it lands on roads, sidewalks and power lines. Plows can’t push a glaze of ice away the way they push snow, and salt needs time to work.
This page scores ice and cold. The Snow Day Calculator scores snow, ice, cold and wind together, so on a snowy night it gives the fuller estimate, and the two pages can show different numbers for the same morning.
FAQ
There’s no single temperature. Each district or school board decides, usually from the wind chill at bus time rather than the air temperature; some publish a guideline, and many decide case by case. In this calculator, a wind chill of about −18°F (−28°C) reaches Maybe and −40° reaches Likely, but schools in milder regions may close at much less extreme cold.
Yes. Districts and school boards sometimes close schools, delay the start or cancel buses when extreme cold makes waiting outside unsafe, even on a clear morning with no snow. In much of Canada, buses can be cancelled while schools stay open.
Both. The biggest factor is the coldest wind chill in the 6, 7 and 8 am readings, when students wait for buses. A smaller factor adds points for an overnight low of −20°F (−29°C) or colder.
It works for any town in the US and Canada, but its scale is set for places used to cold and it has no questions about your district. Schools in milder regions, such as the South and the mid-Atlantic, may close or delay at much less extreme cold than it assumes, so a low number there means less.
This page is for cold and ice. The Snow Day Calculator scores snow, ice, cold and wind together, so on a snowy night it gives the fuller estimate. When 1 inch (2.5 cm) or more of snow is forecast, the result here links to it.
Its accuracy hasn’t been measured: the point values are first estimates, not checked against real closing records. Treat the percentage as an estimate, not a reliable prediction.
Some do, but many school boards keep schools open and cancel buses in extreme cold instead. Canadian places show °C and km/h, and the result notes that buses can be cancelled while schools stay open.
No. This site isn’t affiliated with any school, district, school board or weather service. Always check your district’s or school board’s own announcements.
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