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Flood in Cass County, Iowa
51 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.
Cass County, Iowa, has 51 flood events in the NCEI record since 1950, with at least one in 14 different years.
May is the busiest month, with 22 of the recorded events. The last 20 years account for 36 events against 15 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 0.7% of the 7,383 flood events recorded in Iowa; its 9.0 per 100 square miles compares with 13.2 statewide.
Compared with Iowa
| Measure | Cass County | Iowa | US |
|---|---|---|---|
| Flood events since 1950 | 51 | 7,383 | 183,559 |
| Per 100 square miles | 9.0 | 13.2 | 5.2 |
| Per 10,000 residents | 39.1 | 23.1 | 5.5 |
| Deaths recorded | 0 | 18 | 2,961 |
| Busiest month | May | June | June |
By year
Seasonality
0Feb
1Mar
4Apr
3May
22Jun
12Jul
3Aug
2Sep
2Oct
2Nov
0Dec
0
Recorded events
All 51 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 |
|---|---|---|---|---|---|---|---|
| 24 Sep 2019 | Flash Flood | — | $5K | — | — | — | County |
| 24 May 2019 | Flash Flood | — | $20K | — | — | — | County |
| 24 May 2019 | Flash Flood | — | $50K | — | — | — | County |
| 14 Mar 2019 | Flood | — | — | — | — | — | County |
| 13 Mar 2019 | Flood | — | $10K | — | — | — | County |
| 26 May 2016 | Flash Flood | — | $25K | — | — | — | County |
| 26 May 2016 | Flash Flood | — | $25K | — | — | — | County |
| 9 Sep 2014 | Flash Flood | — | $15K | — | — | — | County |
| 3 Jun 2014 | Flash Flood | — | $50K | — | — | — | County |
| 11 May 2014 | Flash Flood | — | $100K | — | — | — | County |
| 14 Apr 2012 | Flash Flood | — | $10K | — | — | — | County |
| 12 Jun 2010 | Flood | — | — | $20M | — | — | County |
| 12 Jun 2008 | Flood | — | $10K | $10K | — | — | County |
| 11 Jun 2008 | Flash Flood | — | $25K | — | — | — | County |
| 11 Jun 2008 | Flash Flood | — | $100K | — | — | — | County |
| 8 Jun 2008 | Flash Flood | — | $10K | — | — | — | County |
| 8 Jun 2008 | Flash Flood | — | $10K | — | — | — | County |
| 5 Jun 2008 | Flash Flood | — | $25K | — | — | — | County |
| 5 Jun 2008 | Flash Flood | — | $50K | — | — | — | County |
| 4 Jun 2008 | Flash Flood | — | $50K | — | — | — | County |
| 15 Oct 2007 | Flood | — | $50K | $25K | — | — | County |
| 14 Oct 2007 | Flash Flood | — | $75K | $10K | — | — | County |
| 6 Aug 2007 | Flash Flood | — | $50K | $25K | — | — | County |
| 24 May 2007 | Flood | — | $75K | — | — | — | County |
| 24 May 2007 | Flood | — | $200K | — | — | — | County |
| 24 May 2007 | Flash Flood | — | $250K | $50K | — | — | County |
| 6 May 2007 | Flood | — | $1.0M | — | — | — | County |
| 6 May 2007 | Flash Flood | — | $50K | — | — | — | County |
| 6 May 2007 | Flash Flood | — | $100K | — | — | — | County |
| 6 May 2007 | Flash Flood | — | $200K | — | — | — | County |
| 6 May 2007 | Flash Flood | — | $200K | — | — | — | County |
| 6 May 2007 | Flash Flood | — | $50K | — | — | — | County |
| 6 May 2007 | Flash Flood | — | $200K | — | — | — | County |
| 6 May 2007 | Flood | — | $50K | — | — | — | County |
| 24 Apr 2007 | Flash Flood | — | $50K | — | — | — | County |
| 24 Apr 2007 | Flash Flood | — | $50K | — | — | — | County |
| 22 May 2004 | Flood | — | $100K | $298K | — | — | Forecast zone |
| 23 Mar 2001 | Flood | — | $8K | — | — | — | Forecast zone |
| 15 Mar 2001 | Flood | — | $5K | — | — | — | Forecast zone |
| 26 Jul 2000 | Flash Flood | — | $150K | $50K | — | — | County |
| 7 Aug 1999 | Flash Flood | — | $25K | $5K | — | — | County |
| 16 May 1999 | Flash Flood | — | $100K | — | — | — | County |
| 21 Jul 1998 | Flash Flood | — | $50K | $10K | — | — | County |
| 5 Jul 1998 | Flash Flood | — | $100K | $20K | — | — | County |
| 14 Jun 1998 | Flash Flood | — | $2.0M | $1.2M | — | — | County |
| 14 Jun 1998 | Flood | — | $2.5M | $200K | — | — | Forecast zone |
| 18 Feb 1997 | Flood | — | — | — | — | — | Forecast zone |
| 26 May 1996 | Flood | — | — | — | — | — | Forecast zone |
| 24 May 1996 | Flash Flood | — | $75K | $50K | — | — | County |
| 23 May 1996 | Flood | — | — | — | — | — | Forecast zone |
| 8 May 1996 | Flood | — | $50K | — | — | — | County |
Questions and answers
How many flood events has Cass County had?
51 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 Cass County?
24 Sep 2019 (Flash Flood). Records reach NCEI about 120 days after the month ends.
What was the most damaging flood event recorded in Cass County?
The flood of 12 Jun 2010, with property damage estimated by NCEI at $0 and crop damage at $20M.
How does Cass County compare with Iowa for flood?
9.0 events per 100 square miles against 13.2 statewide; the county holds 51 of the state's 7,383 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.