Alert archive / Wisconsin / Flash Flood Warnings
Flash Flood Warnings in Wisconsin, 2025
40 flash flood warnings in 2025. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of flash flood warnings reaches back to 1986.
Flash Flood Warnings by county
Each county as a circle sized by its count in 2025. Tap one for its archive.
- Flash Flood Warnings
- 40
- Busiest month
- July19 flash flood warnings
- Busiest day
- August 10, 20259 flash flood warnings
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
22 of 40 flash flood warnings covering Wisconsin in 2025 had a flash flood report inside them; 42 of 56 flash flood reports fell inside a warning, on average 86 minutes after it went out.
Wisconsin, 2025
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Flash flood warnings | 40 | 22 | 45% | 56 | 75% | 86 min |
Each office's whole area, 2025
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Duluth, MN: flash flood warnings | 14 | 8 | 43% | 26 | 81% | 78 min |
| NWS Milwaukee, WI: flash flood warnings | 18 | 7 | 61% | 20 | 55% | 138 min |
| NWS Twin Cities, MN: flash flood warnings | 22 | 9 | 59% | 24 | 63% | 62 min |
| NWS Green Bay, WI: flash flood warnings | 6 | 4 | 33% | 12 | 92% | 61 min |
| NWS La Crosse, WI: flash flood warnings | 13 | 8 | 38% | 18 | 89% | 55 min |
An office's figures cover every county it serves, including across state lines.
Verified by the Iowa Environmental Mesonet's Cow, which matches each storm-based warning with the local storm reports inside its polygon while it was in force, within 15 km of its edge: a tornado warning counts as verified on a tornado report, a severe thunderstorm warning on hail of 1 inch or more, a gust of 58 mph or more, or wind damage, a flash flood warning on a flash flood report. The false alarm ratio is the share of warnings with no such report; "inside a warning" is the probability of detection, the share of reports that fell inside one; lead time runs from the warning's issue to each report inside it, counting zero for a report that came first. A warning with no report is not proof nothing happened: reports come from spotters, the public and damage surveys, and are thin where few people live.
The alerts
Every alert, in the order issued. Times are local, Central Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 18, 8:40 AM CDT | Flash Flood Warning | MKX | Milwaukee, Ozaukee, Waukesha | 110 min |
| Jun 18, 4:03 PM CDT | Flash Flood Warning | MKX | Rock | 4 hr |
| Jun 18, 4:32 PM CDT | Flash Flood Warning | MKX | Rock, Walworth | 3 hr |
| Jun 23, 8:24 PM CDT | Flash Flood Warning | MKX | Dane, Iowa | 3 hr |
| Jun 23, 8:48 PM CDT | Flash Flood Warning | ARX | Grant | 117 min |
| Jun 29, 2:42 PM CDT | Flash Flood Warning | GRB | Shawano, Waupaca | 3 hr |
| Jun 29, 2:58 PM CDT | Flash Flood Warning | ARX | Monroe | 2 hr |
| Jul 3, 7:00 PM CDT | Flash Flood Warning | ARX | Grant | 75 min |
| Jul 3, 11:04 PM CDT | Flash Flood Warning | ARX | Clark, Jackson | 5 hr |
| Jul 4, 4:12 AM CDT | Flash Flood Warning | DLH | Burnett, Washburn | 3 hr |
| Jul 5, 7:52 PM CDT | Flash Flood Warning | GRB | Door | 2 hr |
| Jul 11, 3:26 PM CDT | Flash Flood Warning | ARX | Grant | 6 hr |
| Jul 11, 5:00 PM CDT | Flash Flood Warning | ARX | Grant | 4 hr |
| Jul 11, 5:16 PM CDT | Flash Flood Warning | MKX | Dane, Green, Iowa, Lafayette | 3 hr |
| Jul 11, 5:44 PM CDT | Flash Flood Warning | MKX | Lafayette | 3 hr |
| Jul 11, 6:40 PM CDT | Flash Flood Warning | MKX | Dane, Green, Iowa, Lafayette | 3 hr |
| Jul 15, 4:33 PM CDT | Flash Flood Warning | DLH | Bayfield | 3 hr |
| Jul 15, 5:51 PM CDT | Flash Flood Warning | DLH | Ashland, Bayfield, Douglas | 5 hr |
| Jul 15, 6:14 PM CDT | Flash Flood Warning | DLH | Burnett, Douglas, Washburn | 4 hr |
| Jul 15, 6:55 PM CDT | Flash Flood Warning | DLH | Bayfield, Douglas | 3 hr |
| Jul 16, 3:17 PM CDT | Flash Flood Warning | MKX | Marquette | 3 hr |
| Jul 16, 3:26 PM CDT | Flash Flood Warning | GRB | Waushara | 3 hr |
| Jul 16, 4:06 PM CDT | Flash Flood Warning | GRB | Calumet, Outagamie, Winnebago | 3 hr |
| Jul 16, 4:21 PM CDT | Flash Flood Warning | GRB | Outagamie, Waupaca, Waushara, Winnebago | 2 hr |
| Jul 16, 4:36 PM CDT | Flash Flood Warning | MKX | Fond du Lac | 101 min |
| Jul 16, 8:17 PM CDT | Flash Flood Warning | GRB | Manitowoc | 3 hr |
| Aug 9, 8:04 PM CDT | Flash Flood Warning | MKX | Milwaukee, Waukesha | 6 hr |
| Aug 9, 11:14 PM CDT | Flash Flood Warning | MKX | Waukesha | 4 hr |
| Aug 10, 1:07 AM CDT | Flash Flood Warning | MKX | Milwaukee, Waukesha | 4 hr |
| Aug 10, 1:38 AM CDT | Flash Flood Warning | MKX | Ozaukee, Washington | 4 hr |
| Aug 10, 5:16 AM CDT | Flash Flood Warning | MKX | Ozaukee, Washington | 3 hr |
| Aug 10, 6:19 AM CDT | Flash Flood Warning | ARX | Grant | 4 hr |
| Aug 10, 7:59 AM CDT | Flash Flood Warning | MKX | Milwaukee, Ozaukee, Washington, Waukesha | 3 hr |
| Aug 10, 8:55 AM CDT | Flash Flood Warning | MKX | Dodge, Washington, Waukesha | 3 hr |
| Aug 10, 6:10 PM CDT | Flash Flood Warning | ARX | Grant | 3 hr |
| Aug 17, 12:14 AM CDT | Flash Flood Warning | ARX | Grant | 2 hr |
| Aug 17, 10:32 PM CDT | Flash Flood Warning | MPX | Dunn, Pepin, Pierce | 4 hr |
| Aug 18, 7:12 PM CDT | Flash Flood Warning | MKX | Rock | 3 hr |
| Aug 18, 7:38 PM CDT | Flash Flood Warning | MKX | Walworth | 3 hr |
| Sep 9, 6:21 AM CDT | Flash Flood Warning | DLH | Ashland, Bayfield | 3 hr |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Grant County7
- Waukesha County6
- Milwaukee County4
- Ozaukee County4
- Bayfield County4
- Washington County4
- Rock County3
- Dane County3
- Iowa County3
- Lafayette County3
- Douglas County3
- Walworth County2
- Waupaca County2
- Burnett County2
- Washburn County2
- Green County2
- Ashland County2
- Waushara County2
- Outagamie County2
- Winnebago County2
- Shawano County1
- Monroe County1
- Clark County1
- Jackson County1
- Door County1
- Marquette County1
- Calumet County1
- Fond du Lac County1
- Manitowoc County1
- Dodge County1
- Dunn County1
- Pepin County1
- Pierce County1
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20242026
Sources
National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Warning verification from the Mesonet's Cow. Rebuilt daily.