Flood Risk by County in Illinois

Illinois: 102 counties covered

Across 102 Illinois counties with a FEMA flood score, the average national percentile is 52.4, but that average hides real spread between counties, which is why each one gets its own page rather than a single statewide number.

• Cook County, 99.9th percentile, Very High
• DuPage County, 98th percentile, Relatively High
• Lake County, 97.2th percentile, Relatively High
• Will County, 97.9th percentile, Relatively High
• Kane County, 95.5th percentile, Relatively High
• McHenry County, 93.1th percentile, Relatively Moderate
• Winnebago County, 94.4th percentile, Relatively High
• Madison County, 92.3th percentile, Relatively Moderate
• St. Clair County, 94.5th percentile, Relatively High
• Champaign County, 90.4th percentile, Relatively Moderate
• Sangamon County, 91.2th percentile, Relatively Moderate
• Peoria County, 88.7th percentile, Relatively Moderate
• McLean County, 85.2th percentile, Relatively Moderate
• Kendall County, 79.7th percentile, Relatively Moderate
• Rock Island County, 79.5th percentile, Relatively Moderate
• Tazewell County, 84.4th percentile, Relatively Moderate
• LaSalle County, 88.2th percentile, Relatively Moderate
• Kankakee County, 92.5th percentile, Relatively Moderate
• DeKalb County, 83th percentile, Relatively Moderate
• Macon County, 83.3th percentile, Relatively Moderate
• Vermilion County, 76.5th percentile, Relatively Moderate
• Williamson County, 69.9th percentile, Relatively Low
• Adams County, 60.7th percentile, Relatively Low
• Whiteside County, 70.1th percentile, Relatively Low
• Grundy County, 66.5th percentile, Relatively Low
• Boone County, 63.9th percentile, Relatively Low
• Jackson County, 76.5th percentile, Relatively Moderate
• Ogle County, 77th percentile, Relatively Moderate
• Knox County, 49.4th percentile, Relatively Low
• Henry County, 51.5th percentile, Relatively Low
• Coles County, 74.5th percentile, Relatively Moderate
• Macoupin County, 68.7th percentile, Relatively Low
• Stephenson County, 77.9th percentile, Relatively Moderate
• Woodford County, 51.5th percentile, Relatively Low
• Clinton County, 64th percentile, Relatively Low
• Franklin County, 65.7th percentile, Relatively Low
• Marion County, 68.1th percentile, Relatively Low
• Jefferson County, 59th percentile, Relatively Low
• Livingston County, 81.1th percentile, Relatively Moderate
• Monroe County, 32.3th percentile, Very Low
• Effingham County, 49.2th percentile, Relatively Low
• Lee County, 62.5th percentile, Relatively Low
• Christian County, 41.5th percentile, Relatively Low
• Morgan County, 61.2th percentile, Relatively Low
• Fulton County, 57.6th percentile, Relatively Low
• Bureau County, 63.4th percentile, Relatively Low
• Randolph County, 57.8th percentile, Relatively Low
• Montgomery County, 58.7th percentile, Relatively Low
• Logan County, 53.7th percentile, Relatively Low
• McDonough County, 21.1th percentile, Very Low
• Iroquois County, 79.6th percentile, Relatively Moderate
• Saline County, 57.4th percentile, Relatively Low
• Jo Daviess County, 58.5th percentile, Relatively Low
• Fayette County, 49.5th percentile, Relatively Low
• Jersey County, 18th percentile, Very Low
• Shelby County, 48.3th percentile, Relatively Low
• Perry County, 49.8th percentile, Relatively Low
• Douglas County, 60.1th percentile, Relatively Low
• Crawford County, 43.7th percentile, Relatively Low
• Hancock County, 24.2th percentile, Very Low
• Union County, 38.9th percentile, Relatively Low
• Piatt County, 43.7th percentile, Relatively Low
• Bond County, 30.5th percentile, Very Low
• Edgar County, 30th percentile, Very Low
• Warren County, 11th percentile, Very Low
• Wayne County, 35.4th percentile, Relatively Low
• Carroll County, 46.5th percentile, Relatively Low
• Richland County, 41.3th percentile, Relatively Low
• De Witt County, 30.3th percentile, Very Low
• Mercer County, 9.2th percentile, Very Low
• Clark County, 31th percentile, Very Low
• Lawrence County, 58.2th percentile, Relatively Low
• Moultrie County, 49.1th percentile, Relatively Low
• Pike County, 33.7th percentile, Very Low
• Massac County, 43th percentile, Relatively Low
• Washington County, 39th percentile, Relatively Low
• Ford County, 35.6th percentile, Relatively Low
• White County, 44.3th percentile, Relatively Low
• Johnson County, 37.9th percentile, Relatively Low
• Clay County, 38.9th percentile, Relatively Low
• Cass County, 28.1th percentile, Very Low
• Mason County, 47.2th percentile, Relatively Low
• Menard County, 29.4th percentile, Very Low
• Marshall County, 35.1th percentile, Relatively Low
• Greene County, 13.2th percentile, Very Low
• Wabash County, 25.8th percentile, Very Low
• Cumberland County, 33.5th percentile, Very Low
• Jasper County, 28.4th percentile, Very Low
• Hamilton County, 12.5th percentile, Very Low
• Schuyler County, 8.2th percentile, Very Low
• Brown County, 4.1th percentile, Very Low
• Henderson County, 24.7th percentile, Very Low
• Edwards County, 21.5th percentile, Very Low
• Putnam County, 19.6th percentile, Very Low
• Stark County, 11.2th percentile, Very Low
• Scott County, 5.1th percentile, Very Low
• Pulaski County, 15.1th percentile, Very Low
• Gallatin County, 36th percentile, Relatively Low
• Alexander County, 40.5th percentile, Relatively Low
• Calhoun County, 16.1th percentile, Very Low
• Pope County, 17.2th percentile, Very Low
• Hardin County, 15.5th percentile, Very Low