Mascoutah is located in St. clair county Illinois with a geographic area of 9.6 square miles. The total population in Mascoutah is 8,454 with 44.6% male and 55.4% female. Children under age 5 represent 7.8% of the population, under age 18 equal 28.0% of the population and over age 65 is 12.9% of the population. The median household income is $74,937, per capita income is $29,884. There are a total of 2,760 housing units with 75.1% owner occupied. Education includes 22.9% of residents that are high school graduates and 34.0% with a bachelor's degree or higher. The average temperature in Mascoutah in the summer is 76 degrees, and in the winter 27 degrees.