Watertown is located in Codington county South dakota with a geographic area of 18.1 square miles. The total population in Watertown is 22,249 with 49.5% male and 50.5% female. Children under age 5 represent 6.4% of the population, under age 18 equal 24.0% of the population and over age 65 is 17.8% of the population. The median household income is $52,145, per capita income is $29,346. There are a total of 9,764 housing units with 60.8% owner occupied. Education includes 31.2% of residents that are high school graduates and 21.1% with a bachelor's degree or higher. The average temperature in Watertown in the summer is 68 degrees, and in the winter 15 degrees.