Flash Flood in Wisconsin
Every flash flood event the National Weather Service has filed in Wisconsin, year by year, with the most significant episodes. Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
The most significant on the map
The most significant flash flood episodes in Wisconsin.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The record
- Events
- 1,070
- Deaths
- 14
- Injuries
- 21
- Damage
- $1.6 billion
Every year
The most significant
Ranked by deaths, injuries, damage and size together.
- Flash Flooding and Flooding in Wisconsin, August 9 to 13, 2025A historic flash flood and record rainfall occurred over portions of the Milwaukee Metropolitan Area and Southeast WI resulting in damages in the $100s Millions.
- Tornado and Flash Flooding in Wisconsin, July 11 to 14, 2016Thunderstorms brought heavy rain to northwest Wisconsin early Monday, July 11th which helped to saturate the soil. During the day a strong low level jet pumped very moist air into the region.
- Flash Flooding and Flooding in Wisconsin, September 21 to 29, 2016One person was killed near Victory (Vernon County) when a house was swept down a hillside by a mudslide during the early morning hours of the 22nd.
- Flash Flooding in Wisconsin, August 6 to 7, 1998A monumental flash flood event ravaged adjacent portions of Milwaukee and Waukesha counties during the afternoon and evening hours.
- Flash Flooding and Flooding in Wisconsin, June 16 to 18, 2018Multiple rounds of thunderstorms along a stationary boundary starting Friday, June 15th, and persisting through the day June 16th, acted to saturate soils across northwest Wisconsin. Another round of training storms developed the night of the 16th, fed by a moist low-level jet.
- Tornadoes and Flash Flood in Wisconsin, July 16, 1997Severe thunderstorms affected much of northern, central and east-central Wisconsin during the afternoon and evening of July 16 with tornadoes, downburst winds and large hail.
- Tornadoes and Flash Flooding in Wisconsin, June 12 to 13, 2008A series of clusters of strong to severe storms ahead of a cold front moved east/northeast across south-central and sourtheast Wisconsin. Copious amounts of moisture were available that allowed repeated heavy rains.
- Tornadoes and Flash Flooding in Wisconsin, June 7 to 8, 2008A slow-moving surface boundary, nearly parallel with the mid-level flow affected southern Wisconsin during the period of June 7th through June 9th.
- Flash Flooding and Flooding in Wisconsin, August 18 to 31, 2007A warm front lifting northward into Iowa triggered round after round of thunderstorms leading to excessive rainfall across southwest Wisconsin during the evening and overnight hours of August 18-19. Total rainfall amounts of 10 to 15 inches were common.
- Tornadoes and Flash Flooding in Wisconsin, April 17, 2026A severe weather outbreak unfolded across central and north-central Wisconsin during the afternoon and early evening of Friday (4/17). The event was triggered by a surface low-pressure system and cold front across the upper Midwest.
- Tornado and Flash Flooding in Wisconsin, August 20 to 31, 2018An organized and slow moving low pressure area within a very moist airmass resulted in 9 to 15 inches of rain and historic flash flooding from the west side of Madison to Mazomanie, and south to Belleville.
- Tornadoes and Flash Flooding in Wisconsin, April 14, 2026Numerous severe thunderstorms developed across southern Wisconsin during the afternoon and evening hours as a wave of low pressure moved across a stationary front over the region.
- Tornadoes and Flash Flood in Wisconsin, July 20, 2019For the second consecutive day, a line of powerful thunderstorms moved across portions of central and east-central Wisconsin. The worst damage occurred from Wood/Portage counties eastward into the Fox Valley and lakeshore.
- Tornado and Flash Flooding in Wisconsin, August 7 to 11, 2021Several rounds of storms moved across western Wisconsin during the afternoon of August 7th. One of these storms produced an EF3 tornado that started in Boscobel (Grant County) and traveled east/southeast before dissipating south of Blue River (Grant County).
- Flash Flooding in Wisconsin, July 22, 2010Parts of south-central and southeast Wisconsin experienced several rounds of record-setting torrential heavy rains during the afternoon and evening hours of July 22, 2010 that led to flash flooding and damage.
- Tornadoes and Flash Flooding in Wisconsin, June 1, 2000One would be hard pressed to find another day like June 1, 2000 in terms of depth and range of severe, convective weather events across south-central and southeast Wisconsin.
- Flash Flooding and Damaging Wind in Wisconsin, June 28 to 29, 2020During the evening of Sunday, June 28th, a complex of thunderstorms that developed across Iowa previously, moved slowly northward across southern Minnesota and western Wisconsin before stalling Monday morning.
- Flash Flooding and Hail in Wisconsin, September 10 to 11, 2000From 2030 to 2115, 2.15 inches of rain fell at Cedar Falls. NWS cooperative observers measured totals of 4.39 inches at Menomonie and 3.48 inches at Cedar Falls. Several intersections and basements in Menomonie were flooded.
- Tornadoes and Flash Flooding in Wisconsin, June 22, 2024Severe thunderstorms developed across western Wisconsin and moved eastward across southern Wisconsin through the afternoon and evening hours on June 22nd due to passing low pressure and its approaching cold front.
- Tornadoes and Flash Flooding in Wisconsin, August 28 to 31, 2018A line of severe thunderstorms produced widespread wind damage and 18 brief tornadoes across mainly Marquette, Green Lake, Fond du Lac, northern Dodge, and Sheboygan Counties.
- Tornado and Flash Flood in Wisconsin, July 18 to 24, 2019Several rounds of thunderstorms moved across western Wisconsin during the late evening of July 18th into the early morning hours of July 19th. As the initial round of storms moved through, a brief tornado touched down northeast of Westby (Vernon County).
- Flash Flooding and Damaging Winds in Wisconsin, June 8 to 9, 2008A slow-moving surface boundary, nearly parallel with the mid-level flow affected southern Wisconsin during the period of June 7th through June 9th.
- Tornado and Flash Flooding in Wisconsin, August 27 to 31, 2018A line of severe thunderstorms moved across western Wisconsin during the evening of August 27th. A brief tornado touched down and had an intermittent damage path between Tomah and Wyeville (Monroe County). The damage was limited to trees and power poles.
- Tornado and Flash Flooding in Wisconsin, April 15 to 16, 2026An organized area of low pressure tracked along a stationary over the region and brought lines and clusters of strong thunderstorms and heavy rainfall to southern WI. Flash flooding occurred in spots from Rock County to the Milwaukee area.
- Flash Flooding and Hail in Wisconsin, June 25 to 26, 2006Very slow moving clusters of thunderstorms developed across south-central Wisconsin during the early afternoon hours of June 25th.
More
Sources
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24.