Delaware is located in Delaware county Ohio with a geographic area of 20.0 square miles. The total population in Delaware is 41,818 with 49.4% male and 50.6% female. Children under age 5 represent 7.3% of the population, under age 18 equal 24.0% of the population and over age 65 is 13.0% of the population. The median household income is $74,130, per capita income is $33,355. There are a total of 15,471 housing units with 62.7% owner occupied. Education includes 20.9% of residents that are high school graduates and 45.5% with a bachelor's degree or higher. The average temperature in Delaware in the summer is 71 degrees, and in the winter 32 degrees.