Watseka is located in Iroquois county Illinois with a geographic area of 2.9 square miles. The total population in Watseka is 4,956 with 42.9% male and 57.1% female. Children under age 5 represent 5.2% of the population, under age 18 equal 17.2% of the population and over age 65 is 23.3% of the population. The median household income is $38,162, per capita income is $24,915. There are a total of 2,384 housing units with 61.8% owner occupied. Education includes 40.1% of residents that are high school graduates and 9.4% with a bachelor's degree or higher. The average temperature in Watseka in the summer is 72 degrees, and in the winter 27 degrees.