Grinnell is located in Poweshiek county Iowa with a geographic area of 5.7 square miles. The total population in Grinnell is 9,069 with 45.9% male and 54.1% female. Children under age 5 represent 2.5% of the population, under age 18 equal 17.5% of the population and over age 65 is 22.8% of the population. The median household income is $50,668, per capita income is $35,372. There are a total of 3,753 housing units with 57.2% owner occupied. Education includes 34.1% of residents that are high school graduates and 36.1% with a bachelor's degree or higher. The average temperature in Grinnell in the summer is 70 degrees, and in the winter 23 degrees.