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Flood in Union County, Iowa
39 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.
NCEI records 39 flood events in Union County, Iowa, between 1950 and 2026, spread over 15 years.
May is the busiest month, with 12 of the recorded events. The last 20 years account for 27 events against 12 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 0.5% of the 7,383 flood events recorded in Iowa; its 9.2 per 100 square miles compares with 13.2 statewide.
Compared with Iowa
| Measure | Union County | Iowa | US |
|---|---|---|---|
| Flood events since 1950 | 39 | 7,383 | 183,559 |
| Per 100 square miles | 9.2 | 13.2 | 5.2 |
| Per 10,000 residents | 32.5 | 23.1 | 5.5 |
| Deaths recorded | 0 | 18 | 2,961 |
| Busiest month | May | June | June |
By year
Seasonality
0Feb
1Mar
2Apr
0May
12Jun
11Jul
5Aug
4Sep
4Oct
0Nov
0Dec
0
Recorded events
All 39 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 |
|---|---|---|---|---|---|---|---|
| 25 Jun 2019 | Flash Flood | — | $10K | — | — | — | County |
| 5 Sep 2018 | Flash Flood | — | $10K | — | — | — | County |
| 11 Jul 2015 | Flash Flood | — | $50K | — | — | — | County |
| 11 Jul 2015 | Flood | — | $100K | — | — | — | County |
| 10 Sep 2014 | Flood | — | $200K | $50K | — | — | County |
| 9 Sep 2014 | Flash Flood | — | $200K | $50K | — | — | County |
| 16 May 2013 | Flash Flood | — | $10K | — | — | — | County |
| 26 Jun 2011 | Flash Flood | — | $10K | — | — | — | County |
| 25 Jun 2011 | Flash Flood | — | $25K | — | — | — | County |
| 25 Jun 2011 | Flash Flood | — | $10K | — | — | — | County |
| 25 Jun 2011 | Flash Flood | — | $10K | — | — | — | County |
| 11 May 2011 | Flash Flood | — | $250K | $10K | — | — | County |
| 11 May 2011 | Flash Flood | — | $10K | — | — | — | County |
| 19 Sep 2010 | Flash Flood | — | $250K | $25K | — | — | County |
| 12 Jun 2010 | Flood | — | — | $20M | — | — | County |
| 5 Jun 2010 | Flash Flood | — | $10K | — | — | — | County |
| 5 Jun 2010 | Flash Flood | — | $100K | — | — | — | County |
| 5 Jun 2010 | Flood | — | $100K | — | — | — | County |
| 25 May 2010 | Flash Flood | — | $15K | — | — | — | County |
| 25 May 2010 | Flash Flood | — | $10K | — | — | — | County |
| 24 Jul 2008 | Flash Flood | — | $50K | $100K | — | — | County |
| 8 Jun 2008 | Flash Flood | — | $50K | — | — | — | County |
| 4 Jun 2008 | Flash Flood | — | $100K | — | — | — | County |
| 24 Aug 2007 | Flash Flood | — | $75K | $50K | — | — | County |
| 24 Aug 2007 | Flash Flood | — | $50K | $25K | — | — | County |
| 23 Aug 2007 | Flash Flood | — | $100K | $25K | — | — | County |
| 23 Aug 2007 | Flash Flood | — | $25K | $10K | — | — | County |
| 24 May 2004 | Flash Flood | — | $100K | $25K | — | — | County |
| 24 May 2004 | Flash Flood | — | $25K | $5K | — | — | County |
| 22 May 2004 | Flood | — | $100K | $298K | — | — | Forecast zone |
| 23 Mar 2001 | Flood | — | $8K | — | — | — | Forecast zone |
| 15 Mar 2001 | Flood | — | $5K | — | — | — | Forecast zone |
| 5 Jul 2000 | Flash Flood | — | $50K | $25K | — | — | County |
| 31 Jul 1999 | Flood | — | $25K | $10K | — | — | Forecast zone |
| 18 Feb 1997 | Flood | — | — | — | — | — | Forecast zone |
| 26 May 1996 | Flood | — | — | — | — | — | Forecast zone |
| 23 May 1996 | Flood | — | — | — | — | — | Forecast zone |
| 9 May 1996 | Flood | — | — | — | — | — | Forecast zone |
| 8 May 1996 | Flood | — | $50K | — | — | — | County |
Questions and answers
How many flood events has Union County had?
39 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 Union County?
25 Jun 2019 (Flash Flood). Records reach NCEI about 120 days after the month ends.
What was the most damaging flood event recorded in Union County?
The flood of 12 Jun 2010, with property damage estimated by NCEI at $0 and crop damage at $20M.
How does Union County compare with Iowa for flood?
9.2 events per 100 square miles against 13.2 statewide; the county holds 39 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.