Snow Day Calculator — Will School Be Closed Tomorrow?
Wondering will school be closed tomorrow? This free snow day calculator is a fun snow day predictor: enter tomorrow's forecast — snowfall, temperature, wind, precipitation type and timing — and get an estimated chance of a snow day, with a full points breakdown so you can see exactly how the number was reached.
For fun only — this is an estimate based on weather inputs, not an official school closing prediction. Your school district decides; always check its official announcements.
For fun only — this is an estimate based on weather inputs, not an official school closing prediction. Your school district decides; always check its official announcements.
For fun only — this is an estimate based on weather inputs, not an official school closing prediction. Your school district decides; always check its official announcements.
Use the forecast for tomorrow morning — that is when districts usually decide. Snowfall is capped at 8 inches for scoring: beyond that, more snow does not change the estimate. The result is capped at 95% and never reaches 100%, because no estimate is ever certain.
How snow days are actually decided
No calculator closes a school — a person does. In most districts, the superintendent (or a small team) makes the call, usually very early in the morning, after checking the forecast, the roads, and whether the buses can run safely. Here is what they weigh:
- Snowfall and ice. How much snow is expected, and whether freezing rain will glaze the roads. A thin layer of ice can shut down bus routes that would run fine on several inches of snow.
- Temperature and wind chill. Bitter cold can close schools on its own, even on a dry day, because children waiting at bus stops can be at risk.
- Road conditions. Can plows clear the bus routes in time? Are side roads, hills and rural routes passable — not just the main roads?
- Timing. Snow that falls overnight gives plows hours to clear it. The same amount falling between 4 and 8 AM, while buses are rolling out, is far more disruptive.
- Bus safety and staffing. Can the buses run, and can enough drivers, teachers and staff get in? A storm that strands staff can close a school even if the roads look passable.
- Local experience. Districts that see snow all winter have more plows and higher thresholds; districts that rarely see snow may close with just a few inches.
That is why this page is a school closing calculator in the fun sense only: it scores the weather, not the decision. The district's announcement is the only official answer.
How this snow day predictor scores your forecast
The estimator adds up points from six factors. The total, in points, becomes the percentage chance — clamped to a range of 0% to 95%. The maximum possible total is 130 points (80 + 15 + 10 + 10 + 15), so very severe forecasts hit the 95% cap. Nothing here is based on a study or on measured accuracy against real closures: these are simple, transparent rules we chose so you can check the maths yourself.
| Factor | Rule | Points |
|---|---|---|
| Snowfall | 10 points per inch, up to 8 inches | 0–80 |
| Temperature | ≤ 20°F: 15 · 21–28°F: 10 · 29–32°F: 5 · above 32°F: 0 | 0–15 |
| Wind gusts | ≥ 35 mph: 10 · 25–34 mph: 5 · below 25 mph: 0 | 0–10 |
| Timing | Overnight: 10 · Morning (4–8 AM): 10 · Evening: 5 · Afternoon: 0 | 0–10 |
| Precipitation type | Snow: 0 · Mixed: −10 · Rain: −20 | −20–0 |
| Delay already announced | Yes: 15 · No: 0 | 0 or 15 |
What the percentage means
| Chance | Verdict |
|---|---|
| 0–19% | Very unlikely — pack your bag |
| 20–39% | Unlikely, but keep an eye on it |
| 40–59% | Maybe — a real chance |
| 60–79% | Likely — start hoping |
| 80–95% | Very likely — get the sled ready (but still check your district!) |
Worked examples, step by step
Example 1: a big overnight blizzard — 8 inches, 18°F, 40 mph gusts, overnight, no delay announced
| Factor | Input | Points |
|---|---|---|
| Snowfall | 8 inches × 10 | 80 |
| Temperature | 18°F (≤ 20°F) | 15 |
| Wind gusts | 40 mph (≥ 35 mph) | 10 |
| Timing | Overnight | 10 |
| Precipitation type | Snow | 0 |
| Delay already announced | No | 0 |
| Total | 80 + 15 + 10 + 10 + 0 + 0 = 115, capped at 95 | 95% |
Verdict: Very likely — get the sled ready (but still check your district!). Try it in the calculator above — it returns exactly 95%.
Example 2: a light dusting — 1 inch, 34°F, 5 mph, afternoon, no delay announced
| Factor | Input | Points |
|---|---|---|
| Snowfall | 1 inch × 10 | 10 |
| Temperature | 34°F (above 32°F) | 0 |
| Wind gusts | 5 mph (below 25 mph) | 0 |
| Timing | Afternoon | 0 |
| Precipitation type | Snow | 0 |
| Delay already announced | No | 0 |
| Total | 10 | 10% |
Verdict: Very unlikely — pack your bag. One inch in the afternoon, above freezing, is the kind of forecast districts usually drive straight through.
What raises the odds — and what lowers them
Raises the odds: heavy snowfall (the biggest single factor, up to 80 points); very cold temperatures; strong wind gusts that blow snow back across cleared roads; snow falling overnight or during the 4–8 AM commute; and a delay already announced, which suggests the district is already worried.
Lowers the odds: rain instead of snow (20 points off — rain washes snow away and rarely closes schools on its own); mixed precipitation (10 points off); temperatures above freezing; light wind; and snow that falls in the afternoon, giving plows all night to clear it before the first bus.
What this calculator cannot see: whether plows reach your bus route in time, freezing rain arriving after the snow, staff shortages, heating problems at the school, or how many snow days your district has already used. That is the honest limit of any snow day predictor — and why the result is a fun estimate, never a promise.
Snow day or not, your grades still count — check them here.
Open the GPA Calculator →Frequently Asked Questions
Is this snow day calculator accurate?
No — it is a fun estimate, not a prediction. It scores the weather numbers you enter with a simple points model and turns the total into a percentage, capped at 95%. It cannot know your school district's decision, road conditions, bus safety, or staffing. Always check your district's official announcements.
How do schools actually decide whether to close?
Each school district decides for itself, usually early in the morning. Districts weigh snowfall and ice, temperature and wind chill, road conditions and whether buses can run safely, the timing of the storm, and staffing. No single number — and no online calculator — makes the decision for them.
How much snow does it take to cancel school?
There is no single amount. It depends on where you live: districts that rarely see snow may close with just a few inches, while snow-belt districts with many plows may stay open through much bigger storms. Timing matters too — snow falling during the morning commute counts more than snow that stops overnight.
Can cold alone cause a snow day?
Yes, it can. In very cold regions, districts may close or delay school when the temperature or wind chill is dangerously low, even with no snow at all, because children waiting for buses can be at risk. This calculator gives extra points for temperatures at or below 20°F.
Will school be closed tomorrow?
This calculator can only give a fun estimate based on the forecast you enter — it cannot tell you whether your school will actually be closed tomorrow. A low percentage cannot confirm school is open, and a high percentage cannot confirm a closure. Check your school district's website, app, or local news for the official answer.
Why is the result capped at 95% and never 100%?
Because a snow day is a human decision, not a weather fact. Even in a blizzard, a district could stay open, and forecasts can change overnight. Capping the result at 95% is an honest reminder that no estimate is ever certain.
What should I do if the calculator says a snow day is likely?
Treat it as a heads-up, not a day off. Check your district's announcements in the evening and again in the morning, charge your devices, and have a backup plan — but still pack your bag until the district confirms a closure.
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