Peru is located in La salle county Illinois with a geographic area of 10.0 square miles. The total population in Peru is 9,777 with 45.8% male and 54.2% female. Children under age 5 represent 6.7% of the population, under age 18 equal 19.5% of the population and over age 65 is 26.1% of the population. The median household income is $52,635, per capita income is $34,268. There are a total of 4,482 housing units with 71.3% owner occupied. Education includes 33.6% of residents that are high school graduates and 21.8% with a bachelor's degree or higher. The average temperature in Peru in the summer is 72 degrees, and in the winter 27 degrees.