Snow day calculator apps have become a useful resource for families by helping them assess the chances of school closures. This article looks at what a snow day means, why schools decide to close, and how those decisions come together. A snow day is declared when harsh winter weather makes conditions unsafe for students and staff. Heavy snowfall, icy or dangerous roads, extreme cold, and blizzard conditions are common reasons for closures. When a snow day is announced, classes are canceled so students can remain safely at home rather than traveling in risky weather.