National Weather ServiceWisconsinFlash Flood WarningArchive to October 1, 2026
Flash Flood Warnings in Wisconsin
The National Weather Service issued 40 flash flood warnings for Wisconsin in 2025 and 35 a year on average in 2008-2025; in 2021-2025 it had the 33rd most of any state. 2026 through September: 38, 10% above the average of 35 for those months in 2008-2025. Grant was covered most often (78 times since 2008).
How many flash flood warnings does Wisconsin get?
Every flash flood warning that covered part of Wisconsin. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 38 |
| 2025 | 40 |
| 2024 | 49 |
| 2023 | 13 |
| 2022 | 16 |
| 2021 | 20 |
| 2020 | 27 |
| 2019 | 46 |
| 2018 | 60 |
| 2017 | 20 |
| 2016 | 47 |
| 2015 | 21 |
| 2014 | 29 |
| 2013 | 33 |
| 2012 | 15 |
| 2011 | 30 |
| 2010 | 57 |
| 2009 | 35 |
| 2008 | 78 |
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
When in the year does Wisconsin get them?
Sum of 2008-2025; the busiest month is labelled.
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
Where in Wisconsin?
| County or forecast zone | Since 2008 | Since 2023 | Last issued |
|---|---|---|---|
| Grant | 78 | 10 | August 17, 2025 |
| Dane | 51 | 16 | September 19, 2026 |
| Crawford | 48 | 2 | June 22, 2024 |
| Columbia | 45 | 6 | July 14, 2024 |
| Waukesha | 42 | 11 | September 3, 2026 |
| Sauk | 41 | 3 | June 22, 2024 |
| Milwaukee | 39 | 10 | September 3, 2026 |
| Rock | 36 | 13 | June 24, 2026 |
| Douglas | 35 | 8 | July 15, 2025 |
| Richland | 34 | 1 | June 22, 2024 |
| Vernon | 34 | 3 | September 19, 2026 |
| Iowa | 33 | 5 | April 17, 2026 |
The NWS issues these products for counties or forecast zones; a zone can be part of a county or a mountain range.
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
The latest flash flood warnings for Wisconsin in AreaZine's record
NWS Milwaukee/SullivanWarningSeptember 19, 2026
Flash Flood Warning: Dane, WI
Expired 4:00 a.m. CDT, September 19, 2026
NWS La CrosseWarningSeptember 19, 2026
Flash Flood Warning: Vernon, WI
Expired 4:15 a.m. CDT, September 19, 2026
NWS Milwaukee/SullivanWarningSeptember 4, 2026
Flash Flood Warning: Sheboygan, WI
Expired 9:00 a.m. CDT, September 4, 2026
NWS Milwaukee/SullivanWarningSeptember 3, 2026
Flash Flood Warning: Milwaukee, Ozaukee, Washington County and 1 more, WI
Expired 12:15 p.m. CDT, September 3, 2026
NWS Milwaukee/SullivanWarningAugust 10, 2026
Flash Flood Warning: Racine and Walworth, WI
Expired 3:30 a.m. CDT, August 10, 2026
NWS Milwaukee/SullivanWarningJuly 27, 2026
Flash Flood Warning: Kenosha and Racine, WI
Expired 3:00 p.m. CDT, July 27, 2026
NWS Milwaukee/SullivanWarningJuly 8, 2026
Flash Flood Warning: Ozaukee and Washington County, WI
Expired 2:00 a.m. CDT, July 9, 2026
NWS Green BayWarningJuly 8, 2026
Flash Flood Warning: Brown, WI
Expired 7:15 p.m. CDT, July 8, 2026
This list is AreaZine's record of the NWS alert feed, kept since April 6, 2026; the counts above come from the complete IEM archive.
Source: National Weather Service alerts (api.weather.gov).
What is a flash flood warning?
A flash flood warning means flash flooding is happening or about to happen: water rising fast in streams, streets or dry washes, usually within six hours of heavy rain or a dam or levee failure. A warning means the hazard is happening, about to happen, or very likely: act now to protect people and property. The national record · Every warning type in Wisconsin.