Marissa is located in St. clair county Illinois with a geographic area of 7.2 square miles. The total population in Marissa is 1,263 with 49.7% male and 50.3% female. Children under age 5 represent 6.8% of the population, under age 18 equal 20.2% of the population and over age 65 is 28.0% of the population. The median household income is $43,512, per capita income is $25,238. There are a total of 581 housing units with 78.8% owner occupied. Education includes 36.7% of residents that are high school graduates and 13.4% with a bachelor's degree or higher. The average temperature in Marissa in the summer is 74 degrees, and in the winter 27 degrees.
