Rock Falls is a city located in Whiteside County Illinois. With a 2020 population of 8,606, it is the 242nd largest city in Illinois and the 3427th largest city in the United States . Rock Falls is currently declining at a rate of -0.77% annually and its population has decreased by -7.12% since the most recent census, which recorded a population of 9,266 in 2010. Rock Falls reached it's highest population of 10,633 in 1980. Spanning over 4 miles, Rock Falls has a population density of 2,161 people per square mile.
The average household income in Rock Falls is $61,855 with a poverty rate of 15.81%. The median rental costs in recent years comes to $695 per month, and the median house value is $78,000. The median age in Rock Falls is 40.5 years, 37.3 years for males, and 42.6 years for females.