Plainfield is located in Hendricks county Indiana with a geographic area of 25.7 square miles. The total population in Plainfield is 34,224 with 50.8% male and 49.2% female. Children under age 5 represent 5.9% of the population, under age 18 equal 22.9% of the population and over age 65 is 15.4% of the population. The median household income is $65,306, per capita income is $34,795. There are a total of 12,651 housing units with 64.7% owner occupied. Education includes 28.9% of residents that are high school graduates and 35.1% with a bachelor's degree or higher. The average temperature in Plainfield in the summer is 73 degrees, and in the winter 29 degrees.