Lafayette is located in Contra costa county California with a geographic area of 15.0 square miles. The total population in Lafayette is 25,949 with 48.7% male and 51.3% female. Children under age 5 represent 4.0% of the population, under age 18 equal 25.4% of the population and over age 65 is 19.0% of the population. The median household income is $188,140, per capita income is $92,488. There are a total of 9,470 housing units with 71.4% owner occupied. Education includes 3.8% of residents that are high school graduates and 76.9% with a bachelor's degree or higher. The average temperature in Lafayette in the summer is 70 degrees, and in the winter 43 degrees.