Chesterfield is located in St. louis county Missouri with a geographic area of 31.9 square miles. The total population in Chesterfield is 47,603 with 48.3% male and 51.7% female. Children under age 5 represent 5.4% of the population, under age 18 equal 22.1% of the population and over age 65 is 23.2% of the population. The median household income is $120,394, per capita income is $63,521. There are a total of 19,378 housing units with 80.6% owner occupied. Education includes 7.4% of residents that are high school graduates and 72.6% with a bachelor's degree or higher. The average temperature in Chesterfield in the summer is 76 degrees, and in the winter 32 degrees.