Stillwater is a city in Washington County, Minnesota across the St. Croix River from the state of Wisconsin. It is the county seat. The population was 18,225 at the 2010 census. Stillwater is part of the Twin Cities Metro Area.
According to the United States Census Bureau, the city has a total area of 7.98 square miles (20.67 km2); 6.96 square miles (18.03 km2) is land and 1.02 square miles (2.64 km2) is water. State Highways 36, 95, and 96 are three of the community's main routes.
Stillwater receives an average annual snowfall of 42 inches (1,100 mm). Average annual rainfall is 24 in (610 mm). Each year has an average of 14 days above 90 °F (32 °C).