2,607
Recorded events
99
Counties affected
9
Direct deaths
$338.5M
Property damage
Iowa flash flood history: 2,607 recorded events across 99 counties between 1996 and 2026.
Decade by decade
Iowa flash flood history by decade
The 2010s are the busiest decade on record with 1,194 reported flash flood events across Iowa. Earlier decades are thinner because systematic reporting for this hazard expanded over time, not because the weather was calmer.
County ranking
Counties with the most flash flood events in Iowa
| Rank | County | Events | Deaths | Damage | Span |
|---|---|---|---|---|---|
| #1 | Polk County | 118 | 3 | $17.9M | 1996–2025 |
| #2 | Dubuque County | 68 | 0 | $30.6M | 1997–2025 |
| #3 | Story County | 64 | 0 | $4.8M | 1996–2022 |
| #4 | Scott County | 64 | 0 | $1.2M | 1997–2025 |
| #5 | Buchanan County | 60 | 1 | $4.8M | 1997–2025 |
| #6 | Linn County | 58 | 1 | $813K | 1997–2025 |
| #7 | Webster County | 56 | 0 | $4.5M | 1998–2025 |
| #8 | Dallas County | 53 | 0 | $2.0M | 1998–2022 |
| #9 | Johnson County | 49 | 0 | $3.3M | 1997–2024 |
| #10 | Black Hawk County | 44 | 0 | $5.6M | 1999–2025 |
| #11 | Sioux County | 41 | 0 | $1.7M | 1999–2025 |
| #12 | Guthrie County | 41 | 0 | $1.8M | 1998–2024 |
| #13 | Woodbury County | 39 | 0 | $9.6M | 1996–2024 |
| #14 | Appanoose County | 38 | 0 | $3.4M | 2000–2021 |
| #15 | Warren County | 38 | 0 | $2.6M | 1998–2018 |
| #16 | Marion County | 37 | 0 | $2.1M | 1998–2024 |
| #17 | Iowa County | 37 | 0 | $1.4M | 1997–2025 |
| #18 | Lee County | 36 | 0 | $2.1M | 1997–2026 |
| #19 | Clayton County | 36 | 0 | $5.7M | 1999–2025 |
| #20 | Wapello County | 36 | 0 | $4.0M | 2000–2021 |
| #21 | Clinton County | 36 | 0 | $741K | 1997–2025 |
| #22 | Cass County | 34 | 0 | $4.3M | 1996–2019 |
| #23 | Allamakee County | 33 | 0 | $11.1M | 1998–2024 |
| #24 | Monroe County | 33 | 0 | $2.2M | 2000–2024 |
| #25 | Des Moines County | 33 | 0 | $4.2M | 1997–2022 |
Significant events
Deadliest flash flood events in Iowa
| Date | County | Scale | Deaths | Injuries |
|---|---|---|---|---|
| Jun 8, 2008 | Hamilton County | — | 1 | 0 |
| Jul 1, 2014 | Linn County | — | 1 | 1 |
| Feb 19, 1997 | Polk County | — | 1 | 0 |
| Aug 11, 2010 | Polk County | — | 1 | 4 |
| Jul 1, 2018 | Polk County | — | 1 | 0 |
| May 23, 2004 | Buchanan County | — | 1 | 1 |
| Jun 8, 2008 | Wright County | — | 1 | 0 |
| Aug 24, 2016 | Chickasaw County | — | 1 | 0 |
| Jul 19, 1999 | Floyd County | — | 1 | 0 |