Fairmont is located in Marion county West virginia with a geographic area of 8.6 square miles. The total population in Fairmont is 18,443 with 50.0% male and 50.0% female. Children under age 5 represent 6.4% of the population, under age 18 equal 18.1% of the population and over age 65 is 17.3% of the population. The median household income is $45,540, per capita income is $24,659. There are a total of 7,680 housing units with 59.3% owner occupied. Education includes 33.5% of residents that are high school graduates and 27.7% with a bachelor's degree or higher. The average temperature in Fairmont in the summer is 70 degrees, and in the winter 32 degrees.