Deer park is located in Lake county Illinois with a geographic area of 3.7 square miles. The total population in Deer park is 4,005 with 47.4% male and 52.6% female. Children under age 5 represent 5.6% of the population, under age 18 equal 26.9% of the population and over age 65 is 15.4% of the population. The median household income is $161,422, per capita income is $73,578. There are a total of 1,377 housing units with 86.5% owner occupied. Education includes 12.1% of residents that are high school graduates and 69.9% with a bachelor's degree or higher. The average temperature in Deer park in the summer is 74 degrees, and in the winter 27 degrees.