Sussex is located in Waukesha county Wisconsin with a geographic area of 8.0 square miles. The total population in Sussex is 10,884 with 47.3% male and 52.7% female. Children under age 5 represent 4.9% of the population, under age 18 equal 25.9% of the population and over age 65 is 11.3% of the population. The median household income is $94,065, per capita income is $42,440. There are a total of 4,086 housing units with 69.1% owner occupied. Education includes 21.7% of residents that are high school graduates and 42.0% with a bachelor's degree or higher. The average temperature in Sussex in the summer is 66 degrees, and in the winter 17 degrees.