Rock city is located in Stephenson county Illinois with a geographic area of 0.1 square miles. The total population in Rock city is 354 with 47.5% male and 52.5% female. Children under age 5 represent 10.2% of the population, under age 18 equal 33.1% of the population and over age 65 is 14.4% of the population. The median household income is $49,750, per capita income is $24,151. There are a total of 129 housing units with 77.5% owner occupied. Education includes 50.4% of residents that are high school graduates and 7.8% with a bachelor's degree or higher. The average temperature in Rock city in the summer is 74 degrees, and in the winter 27 degrees.