Rock island is located in Rock island county Illinois with a geographic area of 16.9 square miles. The total population in Rock island is 37,651 with 48.9% male and 51.1% female. Children under age 5 represent 6.0% of the population, under age 18 equal 21.7% of the population and over age 65 is 16.5% of the population. The median household income is $48,120, per capita income is $25,596. There are a total of 15,538 housing units with 61.4% owner occupied. Education includes 27.2% of residents that are high school graduates and 23.2% with a bachelor's degree or higher. The average temperature in Rock island in the summer is 74 degrees, and in the winter 27 degrees.
