The Snow Day Calculator uses a variety of weather data sources and algorithms to predict the likelihood of a snow day for a given location. The exact data used may vary depending on the location and the availability of data sources.

Some of the factors that the snow day predictor may consider when making its prediction include current and forecasted temperature, precipitation, wind speed and direction, and historical weather patterns for the area. The algorithm may also take into account the elevation of the location, as well as the specific microclimate of the area.