1,069
Recorded events
72
Counties affected
13
Direct deaths
$1.2B
Property damage
Wisconsin flash flood history: 1,069 recorded events across 72 counties between 1996 and 2026.
Decade by decade
Wisconsin flash flood history by decade
The 2000s are the busiest decade on record with 401 reported flash flood events across Wisconsin. 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 Wisconsin
| Rank | County | Events | Deaths | Damage | Span |
|---|---|---|---|---|---|
| #1 | Grant County | 69 | 0 | $24.3M | 1997–2025 |
| #2 | Dane County | 47 | 1 | $48.3M | 1996–2024 |
| #3 | Vernon County | 43 | 2 | $78.2M | 1996–2024 |
| #4 | Crawford County | 40 | 0 | $32.8M | 1997–2024 |
| #5 | Milwaukee County | 39 | 2 | $289.7M | 1997–2026 |
| #6 | Waukesha County | 38 | 3 | $190.6M | 1996–2026 |
| #7 | Sauk County | 35 | 0 | $34.6M | 1996–2024 |
| #8 | Bayfield County | 32 | 0 | $3.7M | 1999–2024 |
| #9 | Richland County | 26 | 1 | $14.8M | 1996–2018 |
| #10 | Rock County | 25 | 0 | $34.0M | 1996–2026 |
| #11 | Columbia County | 24 | 0 | $18.3M | 1996–2024 |
| #12 | Dodge County | 22 | 0 | $12.9M | 1996–2024 |
| #13 | Kenosha County | 22 | 0 | $21.6M | 2000–2024 |
| #14 | Buffalo County | 21 | 0 | $7.2M | 1997–2020 |
| #15 | Trempealeau County | 21 | 0 | $5.6M | 1998–2024 |
| #16 | Lafayette County | 20 | 0 | $2.1M | 1996–2024 |
| #17 | Green County | 19 | 0 | $9.1M | 1996–2026 |
| #18 | Monroe County | 18 | 0 | $31.9M | 1998–2024 |
| #19 | Walworth County | 18 | 0 | $12.7M | 1998–2026 |
| #20 | Chippewa County | 18 | 0 | $1.1M | 2000–2022 |
| #21 | Jefferson County | 17 | 0 | $104.4M | 1996–2026 |
| #22 | Eau Claire County | 17 | 1 | $4.9M | 2000–2026 |
| #23 | Racine County | 17 | 0 | $5.4M | 1998–2026 |
| #24 | St. Croix County | 16 | 1 | $8.7M | 2001–2020 |
| #25 | Ozaukee County | 16 | 0 | $11.5M | 1996–2026 |
Significant events
Deadliest flash flood events in Wisconsin
| Date | County | Scale | Deaths | Injuries |
|---|---|---|---|---|
| Aug 6, 1998 | Waukesha County | — | 2 | 1 |
| Jul 22, 2010 | Milwaukee County | — | 1 | 0 |
| Aug 10, 2025 | Milwaukee County | — | 1 | 0 |
| Aug 19, 2007 | Richland County | — | 1 | 0 |
| Jun 29, 2020 | St. Croix County | — | 1 | 0 |
| Jun 17, 2018 | Ashland County | — | 1 | 0 |
| May 9, 2004 | Vernon County | — | 1 | 0 |
| Aug 20, 2018 | Dane County | — | 1 | 0 |
| Sep 22, 2016 | Vernon County | — | 1 | 0 |
| Sep 11, 2000 | Eau Claire County | — | 1 | 1 |