209
Recorded events
2
Direct deaths
0
Direct injuries
$7.2M
Property damage
Flood in Cook County, Illinois: 209 recorded events between 1998 and 2026. The strongest on record measured 0. That places the county #10 nationally and #1 statewide for this hazard.
Decade by decade
Flood in Cook County, Illinois: events per decade
Reporting practice changed over time — early decades are undercounted, not calmer.
The busiest decade for flood in Cook County is the 2020s, when 95 of the county's 209 recorded events were logged. Comparing decades is useful for spotting active periods, but the earliest years are thin because systematic reporting for this hazard began later.
Within the Cook County archive, flood makes up 7.9% of all recorded severe weather across 8 hazard types. Nationally the county sits at #10 for this hazard and #1 within Illinois, putting it in the 99.7 percentile of all U.S. counties.
Seasonality
Events by month
May is the peak month for flood in Cook County with 38 recorded events, while Nov is the quietest. Seasonality here is a property of the archive as much as the climate: reports cluster where population and spotter networks are densest.
Significant events
Deadliest on record
| Date | Location | Scale | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Sep 13, 2008 | KIMBERLY HGTS | 0 | 1 | 0 | $0 |
| Aug 4, 1998 | COUNTYWIDE | 0 | 1 | 0 | $0 |
Most recent
Latest recorded events
| Date | Location | Magnitude | Damage |
|---|---|---|---|
| Apr 17, 2026 | CHICAGO BOTANIC GARDEN | — | $0 |
| Apr 17, 2026 | WHEELING | — | $0 |
| Jan 8, 2026 | WHEELING | — | $0 |
| Aug 12, 2025 | NEAR WEST SIDE | 0 | $0 |
| Aug 12, 2025 | PILSEN | 0 | $0 |
| Aug 12, 2025 | HOMETOWN | 0 | $0 |
| Aug 12, 2025 | EAST GARFIELD PARK | 0 | $0 |
| Aug 12, 2025 | EDGEWATER | 0 | $0 |
| Aug 12, 2025 | BUCKTOWN | 0 | $0 |
| Aug 12, 2025 | LINCOLN PARK | 0 | $0 |
Other hazards here
More from Cook County
- Thunderstorm Wind 1,384
- Hail 639
- Flash Flood 191
- Tornado 85
- Heavy Rain 61
- Lightning 57
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
After heavy rain and flash flooding across much of southern Cook County from the early morning through the afternoon of September 13th, flooding continued across many locations through the evening hours and into the early morning hours of September 14th, when another wave of heavy rain moved across the area. A elderly man fell head first into a flooded window well and drowned in Oak Lawn. He was trying to clear a plugged drain in the window well.
Officials in Des Plaines urged residents along the Des Plaines River to evacuate as waters rose to near record levels. An estimated 25 residents of the Big Bend Drive area were rescued by firefighters using boats. Other rescues occurred on Berry Lane and Mill Street. River Road was closed through Des Plaines and Mt. Prospect. Many roads in River Forest were closed.
The combination of heavy rain and melting snow caused flooding across parts of Chicago including flooded roads and numerous flooded basements. Part of the roof of a grocery store in Glencoe collapsed from the weight of rain and melting snow. No injuries were reported.
Quick answers
Frequently asked
How many flood events are on record in Cook County, Illinois?
209 flood events are recorded in Cook County between 1998 and 2026, causing 2 direct deaths.
What is the strongest flood recorded in Cook County?
The strongest flood on record in Cook County measured 0.
Where does the flood data for Cook County come from?
All events come from the NOAA/NCEI Storm Events Database, the federal public-domain archive of severe weather reports. Dates are UTC, damage is as reported and not inflation-adjusted, and the most recent entries may still be revised.
Cite this page
“Flood in Cook County, Illinois.” Severe Weather History. severeweatherhistory.com/county/illinois/cook-county/flood/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.