Plainfield is located in Will county Illinois with a geographic area of 24.7 square miles. The total population in Plainfield is 44,857 with 48.5% male and 51.5% female. Children under age 5 represent 5.9% of the population, under age 18 equal 30.5% of the population and over age 65 is 9.3% of the population. The median household income is $131,241, per capita income is $45,365. There are a total of 13,365 housing units with 89.5% owner occupied. Education includes 13.4% of residents that are high school graduates and 58.0% with a bachelor's degree or higher. The average temperature in Plainfield in the summer is 74 degrees, and in the winter 27 degrees.