Duncanville is located in Dallas county Texas with a geographic area of 11.2 square miles. The total population in Duncanville is 39,096 with 48.6% male and 51.4% female. Children under age 5 represent 7.4% of the population, under age 18 equal 25.8% of the population and over age 65 is 15.7% of the population. The median household income is $57,614, per capita income is $25,873. There are a total of 13,573 housing units with 64.8% owner occupied. Education includes 28.2% of residents that are high school graduates and 25.2% with a bachelor's degree or higher. The average temperature in Duncanville in the summer is 83 degrees, and in the winter 49 degrees.