Gridley is located in Livingston county Illinois with a geographic area of 1.2 square miles. The total population in Gridley is 1,384 with 45.3% male and 54.7% female. Children under age 5 represent 7.3% of the population, under age 18 equal 27.6% of the population and over age 65 is 19.9% of the population. The median household income is $59,464, per capita income is $29,661. There are a total of 559 housing units with 76.7% owner occupied. Education includes 34.2% of residents that are high school graduates and 27.2% with a bachelor's degree or higher. The average temperature in Gridley in the summer is 74 degrees, and in the winter 27 degrees.