These Midwest Counties Are Under Flood Warnings due to Storms

Rain storms across parts of the Midwest have pushed major waterways in the region past the flood stage, and many communities are on high alert. As of Tuesday, August 18th, the National Weather Service had issued standing flood warnings to over 40 counties in Illinois, Indiana, and Nebraska. These counties are home to nearly 2.8 million people collectively, and in many of them, flood warnings are expected to remain in effect into next week. 

The Wabash or White Rivers run through many of the impacted counties, and recent rainfall is expected to cause portions of these rivers to swell more than five feet above flood stage. Overflowing rivers have already flooded roadways and homes in parts of the region where water levels are not forecasted to peak until the weekend. 

Flood warnings are only issued by the NWS when hazardous floods are either imminent or underway, and impacted populations are advised to take precautionary action. Flooding kills an average of 118 Americans each year, and according to the NWS, 230 people in the U.S. were killed by floods in 2025 alone, the most of any year since 1972. 

Using data from the NWS, Climate Crisis 247 identified the counties where the most people are currently under a standing flood warning. We ranked all 42 counties with a flood warning as of August 18, 2026, on their total population using data from the U.S. Census Bureau’s 2024 American Community Survey. Only the 11 most populous counties with a flood warning that is expected to stay in effect until at least August 19th are listed. 

It is important to note that standing county-level flood warnings do not necessarily indicate flood danger for the entire region. Rather, these warnings are typically issued for isolated areas, often along rivers. In the counties on this list, flood risk is largely confined to communities along sections of the Wabash or White Rivers. 

 11. Adams County, Indiana

• Standing flood warning extends until: 11:00 am, Thursday, August 20 (issued on Tuesday, August 18)
• Major population center in county: Decatur, Indiana
• Major river in county: Wabash River
• County population: 36,227

 10. Lawrence County, Indiana

• Standing flood warning extends until: 10:00 am, Sunday, August 23 (issued on Tuesday, August 18)
• Major population center in county: Bedford, Indiana
• Major river in county: East Fork White River
• County population: 45,102

 9. Jackson County, Indiana

• Standing flood warning extends until: 2:00 am, Thursday, August 20 (issued on Tuesday, August 18)
• Major population center in county: Brownstone, Indiana
• Major river in county: East Fork White River
• County population: 46,660

 8. Vermilion County, Illinois

• Standing flood warning extends until: 6:00 am, Monday, August 24 (issued on Tuesday, August 18)
• Major population center in county: Newport, Illinois
• Major river in county: Wabash River
• County population: 72,386

 7. Morgan County, Indiana

• Standing flood warning extends until: 7:00 am, Friday, August 21 (issued on Monday, August 17)
• Major population center in county: Martinsville, Indiana
• Major river in county: White River
• County population: 72,659

 6. Vigo County, Indiana

• Standing flood warning extends until: 11:00 am, Tuesday, August 25 (issued on Monday, August 17)
• Major population center in county: Terre Haute, Indiana
• Major river in county: Wabash River
• County population: 106,109

 5. Madison County, Indiana

• Standing flood warning extends until: 2:00 am, Thursday, August 20 (issued on Monday, August 17)
• Major population center in county: Anderson, Indiana
• Major river in county: White River
• County population: 131,900

 4. Monroe County, Indiana

• Standing flood warning extends until: 3:05 pm, Saturday, August 22 (issued on Monday, August 17)
• Major population center in county: Bloomington, Indiana
• Major river in county: White River
• County population: 140,965

 3. Tippecanoe County, Indiana

• Standing flood warning extends until: 3:12 pm, Friday, August 21 (issued on Tuesday, August 18)
• Major population center in county: Lafayette, Indiana
• Major river in county: Wabash River
• County population: 189,071

 2. Hamilton County, Indiana

• Standing flood warning extends until: 2:00 am, Thursday, August 20 (issued on Monday, August 17)
• Major population center in county: Noblesville, Indiana
• Major river in county: White River
• County population: 365,056

 1. Marion County, Indiana

• Standing flood warning extends until: 9:30 am, Wednesday, August 19 (issued on Monday, August 17)
• Major population center in county: Indianapolis, Indiana
• Major river in county: White River
• County population: 975,809