Watertown is a city located in Codington County, South Dakota. With a 2020 population of 22,285, it is the 5th largest city in South Dakota (after Sioux Falls, Rapid City, Aberdeen, and Brookings) and the 1692nd largest city in the United States. Watertown is currently growing at a rate of 0.30% annually and its population has increased by 3.74% since the most recent census, which recorded a population of 21,482 in 2010. Spanning over 26 miles, Watertown has a population density of 1,230 people per square mile.
The average household income in Watertown is $66,722 with a poverty rate of 14.02%. The median rental costs in recent years comes to $743 per month, and the median house value is $162,600. The median age in Watertown is 37.1 years, 36.3 years for males, and 38.6 years for females. For every 100 females there are 95.6 males.