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Flood in Delaware County, Iowa
44 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 44 flood events in Delaware County, Iowa, between 1950 and 2026, spread over 15 years.
May is the busiest month, with 18 of the recorded events. The last 20 years account for 30 events against 14 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 0.6% of the 7,383 flood events recorded in Iowa; its 7.6 per 100 square miles compares with 13.2 statewide.
Compared with Iowa
| Measure | Delaware County | Iowa | US |
|---|---|---|---|
| Flood events since 1950 | 44 | 7,383 | 183,559 |
| Per 100 square miles | 7.6 | 13.2 | 5.2 |
| Per 10,000 residents | 25.1 | 23.1 | 5.5 |
| Deaths recorded | 0 | 18 | 2,961 |
| Busiest month | May | June | June |
By year
Seasonality
0Feb
1Mar
0Apr
4May
18Jun
9Jul
7Aug
2Sep
1Oct
2Nov
0Dec
0
Recorded events
All 44 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 |
|---|---|---|---|---|---|---|---|
| 14 Apr 2026 | Flash Flood | — | — | — | — | — | County |
| 14 Apr 2026 | Flash Flood | — | — | — | — | — | County |
| 24 May 2019 | Flash Flood | — | — | — | — | — | County |
| 1 Oct 2018 | Flash Flood | — | — | — | — | — | County |
| 9 Jun 2018 | Flash Flood | — | — | — | — | — | County |
| 22 Jul 2017 | Flash Flood | — | $1K | — | — | — | County |
| 21 Jul 2017 | Flash Flood | — | — | — | — | — | County |
| 23 Sep 2016 | Flood | — | $150K | — | — | — | County |
| 19 Jun 2014 | Flash Flood | — | — | — | — | — | County |
| 8 Jul 2013 | Flash Flood | — | $50K | — | — | — | County |
| 26 Jun 2013 | Flash Flood | — | — | — | — | — | County |
| 29 May 2013 | Flash Flood | — | — | — | — | — | County |
| 29 May 2013 | Flash Flood | — | — | — | — | — | County |
| 13 Aug 2010 | Flash Flood | — | $5K | — | — | — | County |
| 24 Jul 2010 | Flash Flood | — | $25M | — | — | — | County |
| 23 Jul 2010 | Flood | — | $100K | — | — | — | County |
| 23 Jul 2010 | Flood | — | $25M | $1.0M | — | — | County |
| 22 Jul 2010 | Flood | — | — | — | — | — | County |
| 8 Jun 2008 | Flash Flood | — | $25K | — | — | — | County |
| 8 Jun 2008 | Flash Flood | — | — | — | — | — | County |
| 1 Jun 2008 | Flood | — | $4.2M | — | — | — | County |
| 30 May 2008 | Flood | — | — | — | — | — | County |
| 26 May 2008 | Flood | — | — | — | — | — | County |
| 25 May 2008 | Flash Flood | — | — | — | — | — | County |
| 25 May 2008 | Flash Flood | — | $100K | — | — | — | County |
| 25 May 2008 | Flash Flood | — | — | — | — | — | County |
| 25 May 2008 | Flash Flood | — | — | — | — | — | County |
| 25 Apr 2008 | Flash Flood | — | — | — | — | — | County |
| 1 Apr 2008 | Flood | — | — | — | — | — | County |
| 7 Oct 2007 | Flash Flood | — | $500K | — | — | — | County |
| 31 May 2004 | Flood | — | — | — | — | — | Forecast zone |
| 30 May 2004 | Flash Flood | — | $3K | — | — | — | County |
| 23 May 2004 | Flood | — | — | — | — | — | Forecast zone |
| 23 May 2004 | Flash Flood | — | $50K | — | — | — | County |
| 22 May 2004 | Flash Flood | — | $5K | — | — | — | County |
| 22 Aug 2002 | Flash Flood | — | — | — | — | — | County |
| 3 Jun 2002 | Flash Flood | — | — | — | — | — | County |
| 1 Jun 2000 | Flood | — | — | — | — | — | Forecast zone |
| 31 May 2000 | Flash Flood | — | — | — | — | — | County |
| 8 Jun 1999 | Flash Flood | — | — | — | — | — | County |
| 17 May 1999 | Flood | — | — | — | — | — | Forecast zone |
| 16 May 1999 | Flash Flood | — | — | — | — | — | County |
| 16 May 1999 | Flash Flood | — | — | — | — | — | County |
| 20 Feb 1997 | Flash Flood | — | — | — | — | — | County |
Questions and answers
How many flood events has Delaware County had?
44 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 Delaware County?
14 Apr 2026 (Flash Flood). Records reach NCEI about 120 days after the month ends.
What was the most damaging flood event recorded in Delaware County?
The flood of 23 Jul 2010, with property damage estimated by NCEI at $25M and crop damage at $1.0M.
How does Delaware County compare with Iowa for flood?
7.6 events per 100 square miles against 13.2 statewide; the county holds 44 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.