Warren County, Illinois Basics:
Warren County Illinois - Government Site
Population: 17,808
Area: 542 square miles
County seat: Monmouth
Area code(s) in use: 309
Time zone: CST
High school graduate or higher: 86.4%
Bachelor's degree or higher: 18.7%
Median household income: $41,138
Persons in poverty: 15.4%
Home ownership rate: 71.6%
Mean travel time to work: 18.8 minutes