About Snow Day Calculator
Snow Day Calculator is one of the most trusted snow day predictors in the United States and Canada. Since 2007, we have helped millions of students, families, and educators estimate school closure chances during winter weather.
Our Story
What began as a middle-school side project grew into a widely used tool with more than 5 million yearly users. The founder built Snow Day Calculator with one simple goal: give students a reliable way to estimate whether they might have a snow day.
In 2007, the original version required manual weather entry. By 2010, we launched automated National Weather Service data ingestion with instant predictions for US ZIP codes. In 2011, we launched iOS and Android apps and were featured by major outlets including The New York Times, The Wall Street Journal, TIME, and NPR.
How It Works
Our algorithm combines several factors to produce an accurate snow day probability:
- Real-time weather data - We use the latest Weather.gov forecast, including expected snowfall, temperature, wind speed, and icy conditions.
- Storm timing - Overnight and early-morning storms are weighted more heavily because they affect opening decisions the most.
- Historical patterns - Our system incorporates how nearby districts have responded to similar conditions in the past.
- School type - Different school types (public, private, boarding) have different closure thresholds based on infrastructure and policies.
Our Commitment
We are committed to delivering free, accurate, and accessible predictions. Snow Day Calculator will remain free to use. We continuously improve our model and data sources to increase reliability over time.
Contact Us
Have questions, feedback, or ideas? We would love to hear from you. Visit our contact page or follow us on social media.