Mehlville is located in St. louis county Missouri with a geographic area of 7.5 square miles. The total population in Mehlville is 28,824 with 48.7% male and 51.3% female. Children under age 5 represent 5.6% of the population, under age 18 equal 18.5% of the population and over age 65 is 20.0% of the population. The median household income is $54,944, per capita income is $33,400. There are a total of 13,108 housing units with 62.9% owner occupied. Education includes 29.2% of residents that are high school graduates and 32.7% with a bachelor's degree or higher. The average temperature in Mehlville in the summer is 77 degrees, and in the winter 32 degrees.