Middletown is located in New castle county Delaware with a geographic area of 12.5 square miles. The total population in Middletown is 22,350 with 47.0% male and 53.0% female. Children under age 5 represent 5.2% of the population, under age 18 equal 25.8% of the population and over age 65 is 18.6% of the population. The median household income is $91,663, per capita income is $41,984. There are a total of 8,317 housing units with 77.4% owner occupied. Education includes 21.4% of residents that are high school graduates and 43.0% with a bachelor's degree or higher. The average temperature in Middletown in the summer is 74 degrees, and in the winter 35 degrees.