Sullivan is located in Illinois. Sullivan, Illinois has a population of 4,532. Sullivan is less family-centric than the surrounding county with 22.41% of the households containing married families with children. The county average for households married with children is 30.11%.
The median household income in Sullivan, Illinois is $59,014. The median household income for the surrounding county is $67,309 compared to the national median of $69,021. The median age of people living in Sullivan is 38.4 years.
The average high temperature in July is 85.8 degrees, with an average low temperature in January of 18.8 degrees. The average rainfall is approximately 40.6 inches per year, with 12.3 inches of snow per year.
