Peoria County is located in the U.S. state of Illinois. The 2020 United States census listed its population at 181,830. Its county seat is Peoria. Peoria County is part of the Peoria metropolitan area.
History
Peoria County was formed in 1825 out of Fulton County. It was named for the Peoria, an Illiniwek people who lived there. It included most of the western valley of the Illinois River up to the Chicago river portage.
Geography
According to the US Census Bureau, the county has a total area of , of which is land and (1.8%) is water. The county is drained by Spoon River, Kickapoo Creek, Elbow Creek, and Copperas Creek.
Climate and weather
In recent years, average temperatures in the county seat of Peoria have ranged from a low of in January to a high of in July, although a record low of was recorded in January 1884 and a record high of was recorded in July 1936. Average monthly precipitation ranged from in January to in May.