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Flood in St. Clair County, Illinois
58 floods and flash floods events in the NCEI Storm Events record, 1950 to 2026. Event types counted: Flood, Flash Flood, Coastal Flood, Lakeshore Flood.
NCEI notes that Storm Data is compiled from a variety of sources including the National Weather Service, other federal, state and local agencies, the media and the public; that property and crop damage figures are estimates; and that some events are recorded by NWS forecast zone rather than by county. FEMA notes that NFIP claim records are redacted and aggregated to protect the privacy of policyholders. Storm records through 30 Jun 2026.
St. Clair County, Illinois, has 58 flood events in the NCEI record since 1950, with at least one in 22 different years.
June is the busiest month, with 19 of the recorded events. The last 20 years account for 38 events against 20 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 0.9% of the 6,507 flood events recorded in Illinois; its 8.8 per 100 square miles compares with 11.7 statewide.
Compared with Illinois
| Measure | St. Clair County | Illinois | US |
|---|---|---|---|
| Flood events since 1950 | 58 | 6,507 | 183,559 |
| Per 100 square miles | 8.8 | 11.7 | 5.2 |
| Per 10,000 residents | 2.3 | 5.1 | 5.5 |
| Deaths recorded | 0 | 61 | 2,961 |
| Busiest month | June | June | June |
By year
Seasonality
0Feb
0Mar
1Apr
6May
9Jun
19Jul
12Aug
7Sep
2Oct
0Nov
0Dec
2
Recorded events
All 58 events, most recent first. Magnitude is hail size, tornado rating or wind speed as recorded.
| Date | Event type | Magnitude | Property damage | Crop damage | Deaths | Injuries | Geography |
|---|---|---|---|---|---|---|---|
| 17 Jul 2025 | Flash Flood | — | $25K | — | — | — | County |
| 6 Jul 2025 | Flash Flood | — | $25K | — | — | — | County |
| 6 Jul 2025 | Flash Flood | — | $10K | — | — | — | County |
| 4 Apr 2025 | Flash Flood | — | $30K | — | — | — | County |
| 14 Jul 2023 | Flash Flood | — | — | — | — | — | County |
| 28 Jul 2022 | Flash Flood | — | — | — | — | — | County |
| 26 Jul 2022 | Flash Flood | — | $10M | — | — | — | County |
| 25 Jul 2021 | Flash Flood | — | — | — | — | — | County |
| 12 Aug 2020 | Flash Flood | — | — | — | — | — | County |
| 12 Aug 2020 | Flash Flood | — | — | — | — | — | County |
| 9 Aug 2020 | Flash Flood | — | — | — | — | — | County |
| 21 Aug 2019 | Flash Flood | — | — | — | — | — | County |
| 12 Aug 2019 | Flash Flood | — | — | — | — | — | County |
| 2 Jun 2019 | Flood | — | $8.1M | — | — | — | County |
| 7 Sep 2018 | Flash Flood | — | — | — | — | — | County |
| 28 Jun 2018 | Flash Flood | — | — | — | — | — | County |
| 25 Jun 2018 | Flash Flood | — | — | — | — | — | County |
| 28 Dec 2015 | Flood | — | — | — | — | — | County |
| 28 Dec 2015 | Flash Flood | — | — | — | — | — | County |
| 19 Jun 2015 | Flash Flood | — | — | — | — | — | County |
| 22 Jun 2013 | Flash Flood | — | — | — | — | — | County |
| 17 Jun 2013 | Flash Flood | — | — | — | — | — | County |
| 1 Jun 2013 | Flash Flood | — | — | — | — | — | County |
| 1 Jun 2013 | Flood | — | $2K | $1K | — | — | County |
| 18 Apr 2013 | Flash Flood | — | — | — | — | — | County |
| 26 Jun 2011 | Flash Flood | — | — | — | — | — | County |
| 22 Apr 2011 | Flash Flood | — | — | — | — | — | County |
| 21 Jul 2010 | Flash Flood | — | — | — | — | — | County |
| 16 Jun 2010 | Flood | — | — | — | — | — | County |
| 10 Jun 2009 | Flash Flood | — | — | — | — | — | County |
| 8 Jun 2009 | Flash Flood | — | — | — | — | — | County |
| 8 May 2009 | Flash Flood | — | — | — | — | — | County |
| 14 Sep 2008 | Flash Flood | — | — | — | — | — | County |
| 6 Jun 2008 | Flash Flood | — | $1K | — | — | — | County |
| 4 Jun 2008 | Flood | — | — | — | — | — | County |
| 30 May 2008 | Flash Flood | — | — | — | — | — | County |
| 26 May 2008 | Flash Flood | — | $20K | — | — | — | County |
| 18 Mar 2008 | Flash Flood | — | — | — | — | — | County |
| 12 Apr 2005 | Flash Flood | — | — | — | — | — | County |
| 5 Jul 2004 | Flash Flood | — | — | — | — | — | County |
| 27 May 2004 | Flash Flood | — | — | — | — | — | County |
| 26 Jun 2003 | Flash Flood | — | — | — | — | — | County |
| 11 Jun 2003 | Flash Flood | — | — | — | — | — | County |
| 12 May 2002 | Flash Flood | — | — | — | — | — | County |
| 1 May 2002 | Flood | — | — | — | — | — | Forecast zone |
| 1 May 2002 | Flood | — | — | — | — | — | Forecast zone |
| 28 Apr 2002 | Flood | — | — | — | — | — | Forecast zone |
| 19 Jul 2001 | Flash Flood | — | — | — | — | — | County |
| 6 Jun 2001 | Flood | — | — | — | — | — | Forecast zone |
| 19 May 2001 | Flood | — | — | — | — | — | Forecast zone |
| 18 Jul 2000 | Flood | — | $200K | — | — | — | County |
| 24 Jun 2000 | Flash Flood | — | — | — | — | — | County |
| 18 Aug 1998 | Flash Flood | — | — | — | — | — | County |
| 5 Aug 1998 | Flood | — | — | — | — | — | County |
| 30 Jul 1998 | Flood | — | — | — | — | — | County |
| 22 Jun 1997 | Flash Flood | — | — | — | — | — | County |
| 1 May 1996 | Flood | — | — | — | — | — | Forecast zone |
| 28 Apr 1996 | Flash Flood | — | — | — | — | — | County |
Questions and answers
How many flood events has St. Clair County had?
58 events in the NCEI Storm Events record between 1950 and 2026. Reporting of floods and flash floods became far more complete after 1996, so early decades undercount.
When was the last recorded flood event in St. Clair County?
17 Jul 2025 (Flash Flood). Records reach NCEI about 120 days after the month ends.
What was the most damaging flood event recorded in St. Clair County?
The flash flood of 26 Jul 2022, with property damage estimated by NCEI at $10M.
How does St. Clair County compare with Illinois for flood?
8.8 events per 100 square miles against 11.7 statewide; the county holds 58 of the state's 6,507 recorded events.
Provenance
NOAA NCEI Storm Events Database, yearly details files through 30 Jun 2026, public domain. County-recorded events plus zone-recorded events whose forecast zone is named for the county (marked "Forecast zone"). Population and area from the US Census Bureau (2021). Built 1 Oct 2026. See the methodology, the Flood hub and the county page.