What is driving the score
Hour by hour, from 6 PM the evening before to 3 PM
How this snow day calculator works
This snow day calculator turns tomorrow's weather forecast into one number: the chance that your school district closes. It does not guess from snowfall alone. Superintendents weigh how much snow falls, what kind of precipitation it is, how cold and windy it gets, and when the storm arrives relative to the morning bus run. The calculator weighs the same things.
- Find your locationType a city, ZIP code or postal code, or share your location. We match it to coordinates and use the forecast for that exact spot.
- Read the hourly forecastWe pull hour-by-hour snowfall, freezing rain, temperature, feels-like temperature and wind gusts for the next school morning. Check before 9 AM on a weekday and you get today. Check later, or on a weekend, and you get the next weekday.
- Focus on the decision windowClosure calls are usually made early in the morning, so we score the hours from 6 PM the evening before through the morning commute, plus a smaller share of snow that keeps falling until mid-afternoon.
- Score it and turn it into a percentageSnow depth, freezing rain, dangerous wind chill, gusty wind and snow falling during the 5 to 9 AM bus run each add points. Your district setting and the number of snow days already used adjust the total, which becomes a snow day percentage and a separate 2-hour delay percentage.
Every result comes with a breakdown, so you can see which part of the forecast is pushing your snow day chance up or down. For the longer explanation, read how snow day predictions work and how accurate they are.
What your snow day percentage means
The percentage is the calculator's estimate that school will be closed, based on the forecast. Think of it as a likelihood, not a verdict.
| Snow day chance | What it usually means | What to do |
|---|---|---|
| Under 10% | School is almost certainly open. Any snow will not stop the buses. | Pack the bag and set the alarm as usual. |
| 10 to 29% | A closure is unlikely, though a delay is plausible. | Check district alerts in the morning before you leave. |
| 30 to 54% | Genuinely uncertain. Storm timing and road conditions will decide. | Have a backup plan and recheck in the evening and early morning. |
| 55 to 79% | A snow day is likely. | Line up childcare and expect an announcement before dawn. |
| 80% and above | A snow day is very likely. | Plan for a day at home, but wait for the official call. |
A 70% chance does not mean 70% of schools will close. It means conditions look bad enough that closing is likely but not certain, in the same way any forecast probability expresses likelihood rather than a promise. The 2-hour delay chance is calculated separately.
How much snow does it take to close school?
There is no magic number. A few inches that closes a school in the Carolinas is a normal Tuesday in Buffalo. Still, it helps to know how this calculator reads snow totals for a typical district when the snow falls overnight and temperatures stay below freezing.
| Snow expected overnight | How the calculator reads it |
|---|---|
| Under 1 inch (2.5 cm) | Almost always a normal school day. Slick spots are possible. |
| 1 to 3 inches (2.5 to 7.5 cm) | Usually open. A 2-hour delay becomes possible, especially if snow falls during the commute. |
| 3 to 6 inches (7.5 to 15 cm) | The swing zone. Timing, wind and your district's habits decide the outcome. |
| 6 to 10 inches (15 to 25 cm) | A snow day is likely for most districts, and close to certain for rural districts with long bus routes. |
| 10 inches (25 cm) or more | Very likely, except in snowbelt districts that are built to handle heavy snow and set a higher bar. |
Warm, wet snow is treated more gently. When morning temperatures climb above about 34°F (1°C), snow tends to melt on pavement, so the calculator discounts it. Freezing rain, deep cold and strong wind work the other way and can close schools well below these totals.
Snow day, 2-hour delay, early dismissal and virtual snow day
Winter weather decisions come in more flavors than a simple open or closed. These are the terms you will hear in district alerts and local news.
- Snow day
- The school building is closed for the whole day because of weather. Classes are canceled or, in some districts, moved online.
- 2-hour delay
- Buses and classes start two hours later than usual. Delays give plows time to finish and the sun time to warm roads. Some districts also use one-hour or three-hour delays.
- Early dismissal
- Students are sent home before the normal end of the day because conditions are expected to get worse in the afternoon.
- Virtual snow day
- The building is closed but learning continues online. You may also hear remote learning day, e-learning day or flexible instruction day.
- Ice day
- A closure caused mainly by freezing rain, sleet or black ice rather than snow depth.
- Cold day
- A closure caused by dangerously low temperatures or wind chill, with or without any snow.
- Calamity day
- A term some states and districts use for weather closures that may not need to be made up. Names and rules differ from place to place.
Our full guide to snow days, delays, early dismissals and virtual days explains how each works and how makeup days are handled.
Why one district closes and the next one stays open
Two schools ten minutes apart can see the same storm and make opposite calls. The weather is the same, but the situation is not. These are the usual reasons.
- Road network and bus routes. Rural, hilly or gravel routes become unsafe long before main roads in a compact town do.
- Plow capacity and budget. Districts in places where snow is routine have more equipment and more experience clearing bus routes quickly.
- Walkers versus bus riders. A district where most children walk faces different risks than one that moves thousands of students by bus.
- Teen drivers and parking lots. Student drivers on icy roads and buried parking lots are a real concern for high schools.
- Buildings and heating. Power outages and extreme cold can close a school even when the roads are fine.
- Calendar flexibility. The number of spare days left, state attendance rules and whether virtual days are allowed all influence the call.
- Neighboring districts. Superintendents often talk to each other before deciding, and a regional closing can pull a borderline district along.
- Timing. Snow that ends at 3 AM gives crews hours to work. Snow that begins at 6 AM can catch buses on the road.
That is why the calculator has a district setting and a snow days used box. Tuning them to your schools makes the percentage far more meaningful than a one-size-fits-all number.
Freezing rain, ice and cold: the closures snow totals miss
Snow depth is only part of the story. A quarter inch of freezing rain can close schools that would stay open for several inches of snow, because a glaze of ice removes traction from roads, sidewalks and bus steps all at once. Salt and plows cannot always keep up, and tree limbs and power lines add risk.
Cold works differently. When the wind chill drops far enough, exposed skin can be harmed in minutes, school buses can struggle to start, and children waiting at stops are at risk. Many northern districts have a published wind chill cutoff for cold days. Blowing and drifting snow can also close rural roads even when little new snow is falling.
This calculator counts freezing rain hours and accumulation, feels-like temperature and gusts separately from snowfall, so an icy or frigid morning can score high even with a light dusting. Dig deeper in our guides to freezing rain, ice and school closures and cold days and wind chill.
Snow day chances across regions
Local experience shapes closing decisions as much as the forecast does. As a general pattern:
| Region | What tends to close schools |
|---|---|
| Northeast and New England | Snow is routine and plow fleets are strong, so closures usually need 6 inches or more, ice, or a major nor'easter. Deep cold can also close schools. |
| Great Lakes and Midwest | Lake-effect snow bands, blowing snow and very low wind chills. Cold days are common in the coldest cities. |
| Mountain West and Plains | Heavy snow is normal. Wind, drifting and ground blizzards that close rural roads matter more than totals. |
| Mid-Atlantic and the South | Low snow tolerance and fewer plows. An inch or two, or a light glaze of ice, can close schools. |
| Pacific Northwest | Occasional snow on hilly roads brings disruption quickly because equipment and experience are limited. |
| Canada | Many school boards cancel buses rather than closing buildings, often because of freezing rain, snow squalls or extreme cold. |
| United Kingdom and Ireland | Even light snow can close schools because of staffing, travel and safety rules. |
Use the district setting to reflect your own area: "Rarely" for places that handle snow well, "Easily" for places where a dusting makes news.
How accurate is a snow day predictor?
A snow day predictor is only as good as the forecast behind it and the guesswork about human decisions. Forecasts are most dependable a day or two out. They get shakier when a storm is days away, when temperatures sit near freezing, or when the rain and snow line runs through your town. Narrow bands of heavy snow can also miss one town and bury the next.
The calculator reflects that uncertainty. Each result carries a forecast confidence label, and predictions three or more days out are pulled back from extremes. The best habit is to check in the evening for the first look, again before bed, and once more early in the morning, since forecasts update through the night. Treat the number as a planning tool and your district's alert as the final word.
Getting ready for a possible snow day
When your percentage climbs into the toss-up zone, a few minutes of preparation pays off. Sign up for your district's text or email alerts, charge phones and laptops, line up childcare or a work-from-home plan, and make sure boots, gloves and warm layers are easy to find. If you drive, fuel up and clear the whole car of snow before heading out.
Our snow day checklist for the night before covers parents, students, teachers and commuters, including safe shoveling and power outage basics.
Snow day guides
Snow day calculator questions
How does a snow day calculator work?
A snow day calculator turns the weather forecast for your location into the chance that school closes. This one reads the hourly forecast for snowfall, freezing rain, temperature, wind chill and wind gusts, concentrates on the hours between the evening before and the morning bus run, scores each factor, adjusts for how easily your district closes, and shows the result as a percentage. The full method is explained in how snow day predictions work.
How accurate is this snow day predictor?
It is an estimate, not an official decision. Weather forecasts are most dependable within a day or two of the event, and the final call depends on local roads, bus routes and human judgment that no weather model can see. The forecast confidence label shows how far ahead you are looking. Use the percentage as a guide, then wait for your district's announcement.
How much snow does it take to cancel school?
There is no single number. As a rough guide for a typical district, under an inch rarely closes school, 1 to 3 inches usually means a normal day or a delay, 3 to 6 inches is the toss-up range, and 6 inches or more makes a snow day likely. Ice, deep cold, strong wind and snow that falls during the morning commute all lower those thresholds.
What does a 70% snow day chance mean?
It means the forecast looks bad enough that a closure is likely but not certain. It does not mean 70% of schools will close, or that school will shut for 70% of the day. And a 20% chance still comes up about one time in five, so a low number is not a promise.
Can school close for ice or cold even when there is no snow?
Yes. A thin glaze of freezing rain can make roads, sidewalks and bus steps dangerous, and many districts close for it even when almost no snow falls. Extreme cold and wind chill can also close schools, sometimes called a cold day, because buses may not start and children cannot safely wait outside. Read more in our guides to ice and school closures and cold days.
What is the difference between a snow day and a 2-hour delay?
On a snow day the school building is closed for the day. On a 2-hour delay, buses and classes start two hours later than normal, which gives road crews time to finish plowing and lets the sun warm the pavement. Our calculator shows a separate delay chance. See the full comparison of snow days, delays, early dismissals and virtual days.
When do schools announce snow days?
Many districts decide early in the morning after drivers check the roads, often somewhere between 4:30 and 6 AM. When a big storm is certain, some call it the evening before. Districts usually notify families by text, email, phone call, their website, social media and local TV or radio, so sign up for your district's alerts.
Why was the prediction wrong?
Closures are human decisions. A district may close over one icy hill on a bus route, stay open because plows cleared the roads in time, or pick a delay instead. Forecasts also shift: a storm that arrives a few hours earlier or later, or a temperature that lands just above or below freezing, can change the outcome. Adjusting the district setting helps the result match how your schools usually behave.
Does the calculator work outside the United States?
Yes. It uses a global forecast, so you can check cities in Canada, the United Kingdom, Europe and elsewhere, and switch between inches with Fahrenheit and centimeters with Celsius. Local practices differ, though. For example, many Canadian school boards cancel buses rather than close buildings, and some UK schools close for light snow, so use the district setting to reflect your area.
What does the district setting do?
It scales the weather score up or down. Choose "Rarely" if your district has strong plowing and keeps schools open through most storms, "Typical" if you are unsure, and "Easily" for rural districts with long bus routes, hills or limited plow budgets. Entering the number of snow days already used also nudges the result down once a district has passed its usual allowance, because districts tend to become more reluctant to close again.
Will virtual learning replace snow days?
Many districts now use remote learning days instead of canceling class, but practice varies widely by district and state, and plenty of schools still use traditional snow days, especially when power or internet may fail. This calculator estimates whether school buildings are likely to be closed or delayed. It cannot tell you whether classes will move online.
Are snow days made up?
It depends on your state and district. Many calendars build in a few spare days. After those are used, a district might add days at the end of the year, shorten a break, convert days to remote learning, or request a waiver where the state allows it. Your district calendar and board policy have the specifics.
How far ahead can I check the chance of a snow day?
The calculator looks at the next school morning, so it shows tomorrow's chance, or Monday's if you check on a Friday afternoon or over the weekend. Forecasts are most dependable one to two days out. When the school day is three or more days away, the confidence label drops to low and the percentage is reduced to avoid false certainty.
Is this site free, and is it official?
It is free and has no accounts. It is not connected to any school district, so it cannot confirm a closure. For official decisions use your district's website, alerts or local media. See our privacy page for how location searches are handled.
Where does the weather data come from?
Forecasts come from Open-Meteo, an open weather data service that draws on national weather agency models. We refresh forecasts about every 15 minutes, so checking again in the evening and early morning gives the most current picture.