Snow Day Calculator
Find out if school will be cancelled tomorrow. Enter tomorrow morning's forecast (temperature, snowfall and wind) and get a transparent, rule-based estimate of the chance of a snow day.
💡 What Should I Do?
This is an estimate based on the numbers you enter. Your school district's announcement is the only official answer.
What Is a Snow Day Calculator?
A Snow Day Calculator is a free online tool that predicts whether school will be cancelled due to winter weather conditions. By analyzing temperature, snow accumulation, wind speed, and your location, the calculator gives you a clear estimate plus a breakdown showing which factor is driving the result.
It is useful the night before a storm: parents can plan childcare, students can plan homework, and teachers can prepare for a possible remote or delayed day. It does not replace your district's announcement — it helps you judge how likely one is.
Smart Weighted Model
Snow (40%), temperature (35%) and wind (15%) are scored separately, then a location adjustment is added. Every weight is shown on this page.
Fun & Actionable Results
Instead of boring percentages, get personality-packed results with suggestions like "Charge your devices & plan your day!"
Location-Aware
Optional location personalization gives you insights like "Schools in your area usually close at 10+ cm snowfall."
Score Breakdown
See exactly how each factor — snow, temperature, wind — contributes to your prediction with our visual breakdown.
City-Specific Versions
For cities like Boston, Chicago, NYC, Detroit, Toronto and Ottawa we have separate pages with local context about how those districts decide.
Share Your Results
Share your snow day prediction with friends and family — because snow day excitement is better together!
How Our Cold Day Calculator Makes Predictions
The calculator uses a weighted scoring model based on the factors school districts publicly list in their closure policies: how much snow falls, how cold it is, and whether wind makes travel dangerous.
Enter Conditions
Slide the temperature, snow, and wind inputs to match your current or forecast weather. Optionally select your location type for better accuracy.
Weighted Analysis
Each factor is scored 0-100 and weighted: Snow 40%, Temperature 35%, Wind 15%, Location 10%. This mirrors real-world closure decision factors.
Instant Prediction
Get a result band with a factor-by-factor breakdown, a short explanation of what is driving the score, and practical next steps.
Worked Example: How a Score Is Calculated
Say the forecast for 6 a.m. is -8°C, 12 cm of snow overnight and 25 km/h wind, in a moderate-snow area.
| Factor | Input | Factor score | Weight | Points |
|---|---|---|---|---|
| Snow | 12 cm | 80 | 40% | 32 |
| Temperature | -8°C | 85 | 35% | 29.75 |
| Wind | 25 km/h | 55 | 15% | 8.25 |
| Location | Moderate snow area | — | adjustment | +5 |
| Total | 75 → "Good Chance of Snow Day" |
Scores of 80+ mean conditions are usually severe enough for closures in most districts; 60–79 is a good chance; 30–59 could go either way; below 30 schools usually open. Snow-heavy regions (e.g. Buffalo, Winnipeg) tolerate more snow than places that rarely see it, which is why the location adjustment exists.
Limits: the calculator cannot see things districts also weigh, such as whether plows reach bus routes in time, freezing rain timing, staff shortages or heating failures. That's why the result is a probability band, not a yes/no answer.
More Snow Tools
Besides the snow day calculator, these free tools cover other winter questions:
- Wind chill calculator — "feels like" temperature using the NWS / Environment Canada formula
- Roof snow load calculator — estimate how much weight snow puts on your roof
- Road salt calculator — how much de-icer to use for your driveway or lot
- Commercial snow removal pricing calculator
- See all tools
Snow Day Risk by City and Region
Do you know? Winter disruption risk varies by geographical region and city. A snow day predictor Ontario result may differ from other provinces or states because tolerance and infrastructure differ. Our Local snow report provides region-specific context and trend guidance.
Data Sources, Accuracy & Transparency
This calculator uses the forecast values you enter. Some US city pages can load the current National Weather Service forecast for your ZIP code. Results apply published, rule-based weights — accuracy depends on the forecast you use and on local district policy. Read More
Report Data Issue or Suggest Improvement
If you notice a data issue or want to suggest an improvement to the snow day predictor logic, you can submit feedback through our contact page. Useful feedback helps improve clarity and model behavior over time.
Frequently Asked Questions
Our Snow Day Calculator uses a weighted scoring model that factors in temperature (35%), snow accumulation (40%), wind speed (15%), and your location characteristics (10%). Each factor is scored from 0 to 100, then combined to produce a final prediction — presented in a fun, human-friendly format instead of just a percentage.
It is a rule-based estimate, not a guarantee. The weights reflect the factors districts publicly say they consider (snow, cold, wind, road safety), but each district also weighs buses, staffing and local policy. Always confirm with your school district's official announcement.
Temperatures below -5°C (23°F) significantly increase the chance of school closures, especially when combined with heavy snowfall. Extreme cold below -15°C (-5°F) almost always results in closures for student safety. Wind chill is also a major factor — even if the temperature is -8°C, a strong wind can make it feel like -20°C.
Most school districts consider closing when snowfall exceeds 10-15 cm (4-6 inches). However, this varies widely. Areas that regularly experience heavy snow (like northern Canada) may stay open with 15 cm, while regions that rarely get snow may close schools with as little as 5 cm due to lack of infrastructure and snow removal equipment.
No. This main calculator uses the values you enter — take them from your local forecast for early morning, when districts usually decide (around 5–6 a.m.). Some of our US city pages can load the current National Weather Service forecast by ZIP code. Either way, the result is an estimate, not an official decision.
A Cold Day Calculator is a broader toolkit that helps predict school closures, assess road safety, and manage winter weather conditions. While our Snow Day Calculator focuses on snow-related closures, our growing suite of cold day tools covers extreme cold, ice storms, wind chill, and more — making it your complete winter weather companion.
About Us
Cold Day Calculator is built and maintained by Adi Wasikesha. It started as a simple snow day calculator and now includes calculators for wind chill, roof snow load, road salt and other winter questions.
Every tool explains its formula and its limits on the same page. If you spot an error, email adiwasikesha@gmail.com or use the contact page — corrections are welcome.