Snow Day Predictor for Potomac, MD

Potomac is a smaller community of about 44,965 people that sits in the mid-latitudes, near 39.0°N in Maryland. A winter here typically brings around 5 to 20 inches a winter. Wintry mix and ice — not deep snow — drive most school closings. Because the town falls in the Upland South / Mid-Atlantic climate region, our model's closure threshold for Potomac is tuned to close fairly easily, since snow-clearing equipment here is limited and roads ice quickly.

The percentage at the top of this page isn't a static guess — it's rebuilt each night from Potomac's own Open-Meteo forecast. The model reads seven signals from the overnight-into-morning window: total snowfall, whether any of it is timed for the 2–6 a.m. commute, freezing rain or sleet, the coldest air temperature, the wind chill, the peak wind, and how much snow is already on the ground. With fewer plows and hilly bus routes, 1–3" or any freezing rain is often enough to cancel. Icy bridges and overpasses are the usual reason for a late start.

Because a 2-hour delay clears a lower bar than an outright cancellation, you'll often see delay odds for Potomac even when the closure odds stay modest — that gap is the model flagging a borderline morning. The estimate shifts as the forecast firms up overnight, so it's worth re-checking Potomac's odds the evening before school. Treat it as a well-informed second opinion for planning, never as an official Maryland closing announcement.