Mendon is located in Adams county Illinois with a geographic area of 0.9 square miles. The total population in Mendon is 1,092 with 48.2% male and 51.8% female. Children under age 5 represent 2.8% of the population, under age 18 equal 29.6% of the population and over age 65 is 18.8% of the population. The median household income is $56,000, per capita income is $23,663. There are a total of 394 housing units with 79.7% owner occupied. Education includes 40.4% of residents that are high school graduates and 16.5% with a bachelor's degree or higher. The average temperature in Mendon in the summer is 74 degrees, and in the winter 27 degrees.