Coffeen is located in Montgomery county Illinois with a geographic area of 1.2 square miles. The total population in Coffeen is 640 with 45.2% male and 54.8% female. Children under age 5 represent 6.6% of the population, under age 18 equal 16.3% of the population and over age 65 is 22.3% of the population. The median household income is $35,781, per capita income is $26,697. There are a total of 317 housing units with 78.2% owner occupied. Education includes 49.8% of residents that are high school graduates and 3.5% with a bachelor's degree or higher. The average temperature in Coffeen in the summer is 77 degrees, and in the winter 27 degrees.