In 2018, St. Clair County, IL had a population of 261k people with a median age of 39.6 and a median household income of $59,141. Between 2017 and 2018 the population of St. Clair County, IL declined from 262,479 to 261,059, a -0.541% decrease and its median household income grew from $51,670 to $59,141, a 14.5% increase.
N/A 0% of the people in St. Clair County, IL speak a non-English language, and 98.1% are U.S. citizens.
In 2018, the median property value in St. Clair County, IL was $132,200, and the homeownership rate was 65.8%. Most people in St. Clair County, IL drove alone to work, and the average commute time was 24.5 minutes. The average car ownership in St. Clair County, IL was 2 cars per household.