Castle rock is located in Douglas county Colorado with a geographic area of 34.3 square miles. The total population in Castle rock is 65,176 with 49.7% male and 50.3% female. Children under age 5 represent 7.7% of the population, under age 18 equal 28.8% of the population and over age 65 is 10.4% of the population. The median household income is $113,585, per capita income is $44,419. There are a total of 21,536 housing units with 79.9% owner occupied. Education includes 11.1% of residents that are high school graduates and 53.8% with a bachelor's degree or higher. The average temperature in Castle rock in the summer is 68 degrees, and in the winter 29 degrees.