Manhattan is located in Will county Illinois with a geographic area of 6.7 square miles. The total population in Manhattan is 8,218 with 52.1% male and 47.9% female. Children under age 5 represent 8.7% of the population, under age 18 equal 30.3% of the population and over age 65 is 10.2% of the population. The median household income is $105,726, per capita income is $37,174. There are a total of 2,703 housing units with 86.2% owner occupied. Education includes 22.5% of residents that are high school graduates and 34.6% with a bachelor's degree or higher. The average temperature in Manhattan in the summer is 74 degrees, and in the winter 27 degrees.