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Flood in Lake County, Illinois
100 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.
Lake County, Illinois, has 100 flood events in the NCEI record since 1950, with at least one in 24 different years.
May is the busiest month, with 27 of the recorded events. The last 20 years account for 83 events against 17 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 1.5% of the 6,507 flood events recorded in Illinois; its 22.5 per 100 square miles compares with 11.7 statewide.
Compared with Illinois
| Measure | Lake County | Illinois | US |
|---|---|---|---|
| Flood events since 1950 | 100 | 6,507 | 183,559 |
| Per 100 square miles | 22.5 | 11.7 | 5.2 |
| Per 10,000 residents | 1.4 | 5.1 | 5.5 |
| Deaths recorded | 0 | 61 | 2,961 |
| Busiest month | May | June | June |
By year
Seasonality
1Feb
1Mar
2Apr
10May
27Jun
17Jul
17Aug
4Sep
10Oct
7Nov
1Dec
3
Recorded events
All 100 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 |
|---|---|---|---|---|---|---|---|
| 11 Jun 2026 | Flood | — | — | — | — | — | County |
| 17 Apr 2026 | Flood | — | — | — | — | — | County |
| 17 Apr 2026 | Flood | — | — | — | — | — | County |
| 17 Apr 2026 | Flood | — | — | — | — | — | County |
| 15 Apr 2026 | Flood | — | — | — | — | — | County |
| 15 Apr 2026 | Flood | — | — | — | — | — | County |
| 15 Apr 2026 | Flood | — | — | — | — | — | County |
| 15 Apr 2026 | Flood | — | — | — | — | — | County |
| 15 Apr 2026 | Flood | — | — | — | — | — | County |
| 15 Jul 2024 | Flash Flood | — | — | — | — | — | County |
| 15 Jul 2024 | Flood | — | — | — | — | — | County |
| 15 Jul 2024 | Flood | — | — | — | — | — | County |
| 22 Jun 2024 | Flash Flood | — | — | — | — | — | County |
| 22 Jun 2024 | Flash Flood | — | — | — | — | — | County |
| 22 Jun 2024 | Flash Flood | — | — | — | — | — | County |
| 28 May 2024 | Flood | — | — | — | — | — | County |
| 13 May 2024 | Flash Flood | — | — | — | — | — | County |
| 11 Sep 2022 | Flood | — | — | — | — | — | County |
| 23 Jul 2022 | Flood | — | — | — | — | — | County |
| 23 Jul 2022 | Flash Flood | — | — | — | — | — | County |
| 29 Oct 2020 | Lakeshore Flood | — | — | — | — | — | Forecast zone |
| 17 May 2020 | Flood | — | — | — | — | — | County |
| 17 May 2020 | Flash Flood | — | — | — | — | — | County |
| 17 May 2020 | Flood | — | — | — | — | — | County |
| 17 May 2020 | Flood | — | — | — | — | — | County |
| 15 May 2020 | Flash Flood | — | — | — | — | — | County |
| 15 May 2020 | Flash Flood | — | — | — | — | — | County |
| 29 Apr 2020 | Lakeshore Flood | — | — | — | — | — | Forecast zone |
| 11 Jan 2020 | Lakeshore Flood | — | — | — | — | — | Forecast zone |
| 30 Nov 2019 | Lakeshore Flood | — | — | — | — | — | Forecast zone |
| 31 Oct 2019 | Lakeshore Flood | — | — | — | — | — | Forecast zone |
| 13 Sep 2019 | Flood | — | — | — | — | — | County |
| 13 Sep 2019 | Flood | — | — | — | — | — | County |
| 13 Sep 2019 | Flash Flood | — | — | — | — | — | County |
| 12 Sep 2019 | Flash Flood | — | — | — | — | — | County |
| 11 Sep 2019 | Flash Flood | — | — | — | — | — | County |
| 1 Dec 2018 | Flood | — | — | — | — | — | County |
| 3 Sep 2018 | Flash Flood | — | $20K | — | — | — | County |
| 3 Sep 2018 | Flood | — | — | — | — | — | County |
| 3 Sep 2018 | Flash Flood | — | $50K | — | — | — | County |
| 26 Jun 2018 | Flood | — | — | — | — | — | County |
| 26 Jun 2018 | Flash Flood | — | — | — | — | — | County |
| 30 May 2018 | Flood | — | — | — | — | — | County |
| 21 May 2018 | Flood | — | — | — | — | — | County |
| 14 May 2018 | Flood | — | — | — | — | — | County |
| 14 Oct 2017 | Flash Flood | — | $25K | — | — | — | County |
| 14 Oct 2017 | Flood | — | — | — | — | — | County |
| 12 Jul 2017 | Flood | — | — | — | — | — | County |
| 12 Jul 2017 | Flash Flood | — | $13M | — | — | — | County |
| 12 Jul 2017 | Flood | — | — | — | — | — | County |
| 23 Jul 2016 | Flash Flood | — | — | — | — | — | County |
| 18 Sep 2015 | Flash Flood | — | — | — | — | — | County |
| 18 Jul 2015 | Flash Flood | — | — | — | — | — | County |
| 12 May 2014 | Flash Flood | — | — | — | — | — | County |
| 12 May 2014 | Flood | — | — | — | — | — | County |
| 12 May 2014 | Flash Flood | — | — | — | — | — | County |
| 12 May 2014 | Flash Flood | — | — | — | — | — | County |
| 12 May 2014 | Flash Flood | — | — | — | — | — | County |
| 5 Oct 2013 | Flood | — | — | — | — | — | County |
| 26 Jun 2013 | Flash Flood | — | — | — | — | — | County |
| 26 Jun 2013 | Flash Flood | — | — | — | — | — | County |
| 26 Jun 2013 | Flash Flood | — | — | — | — | — | County |
| 26 Jun 2013 | Flash Flood | — | — | — | — | — | County |
| 17 Apr 2013 | Flash Flood | — | $4.7M | — | — | — | County |
| 18 Jul 2012 | Flood | — | — | — | — | — | County |
| 27 Jul 2011 | Flash Flood | — | — | — | — | — | County |
| 22 Jul 2011 | Flash Flood | — | — | — | — | — | County |
| 29 May 2011 | Flash Flood | — | — | — | — | — | County |
| 25 May 2011 | Flash Flood | — | — | — | — | — | County |
| 13 May 2010 | Flash Flood | — | — | — | — | — | County |
| 13 May 2010 | Flash Flood | — | $500K | — | — | — | County |
| 19 Jun 2009 | Flash Flood | — | — | — | — | — | County |
| 19 Jun 2009 | Flood | — | — | — | — | — | County |
| 27 Dec 2008 | Flash Flood | — | — | — | — | — | County |
| 27 Dec 2008 | Flash Flood | — | $25K | — | — | — | County |
| 2 Jul 2008 | Flood | — | — | — | — | — | County |
| 13 Jun 2008 | Flood | — | $500K | — | — | — | County |
| 23 Aug 2007 | Flood | — | $100K | — | — | — | County |
| 7 Aug 2007 | Flash Flood | — | $10K | — | — | — | County |
| 18 Jul 2007 | Flood | — | — | — | — | — | County |
| 8 Jun 2007 | Flash Flood | — | — | — | — | — | County |
| 21 Mar 2007 | Flash Flood | — | $50K | — | — | — | County |
| 21 Mar 2007 | Flood | — | — | — | — | — | County |
| 27 Jul 2006 | Flood | — | — | — | — | — | County |
| 27 Jul 2006 | Flood | — | — | — | — | — | County |
| 30 May 2006 | Flood | — | — | — | — | — | County |
| 30 May 2006 | Flood | — | — | — | — | — | County |
| 15 Feb 2005 | Flood | — | — | — | — | — | Forecast zone |
| 11 Jun 2004 | Flood | — | — | — | — | — | Forecast zone |
| 30 May 2004 | Flash Flood | — | — | — | — | — | County |
| 22 May 2004 | Flood | — | — | — | — | — | Forecast zone |
| 18 May 2004 | Flash Flood | — | — | — | — | — | County |
| 22 Aug 2002 | Flash Flood | — | — | — | — | — | County |
| 22 Aug 2002 | Flood | — | — | — | — | — | Forecast zone |
| 4 Jun 2002 | Flood | — | — | — | — | — | Forecast zone |
| 23 Oct 2001 | Flood | — | — | — | — | — | County |
| 13 Oct 2001 | Flash Flood | — | $180K | — | — | — | County |
| 12 Jun 2000 | Flood | — | — | — | — | — | Forecast zone |
| 20 May 1996 | Flash Flood | — | — | — | — | — | County |
| 16 May 1996 | Flash Flood | — | — | — | — | — | County |
Questions and answers
How many flood events has Lake County had?
100 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 Lake County?
11 Jun 2026 (Flood). Records reach NCEI about 120 days after the month ends.
What was the most damaging flood event recorded in Lake County?
The flash flood of 12 Jul 2017, with property damage estimated by NCEI at $13M.
How does Lake County compare with Illinois for flood?
22.5 events per 100 square miles against 11.7 statewide; the county holds 100 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.