Grant County, Wisconsin severe weather history spans 825 recorded events between 1954 and 2026. The dominant hazard is thunderstorm wind, accounting for 40.1% of all recorded events. It ranks #269 nationally and #2 in Wisconsin.
825
Recorded events
2
Direct deaths
13
Direct injuries
$65.6M
Property damage
The record
What the Grant County, Wisconsin severe weather history record shows
Across the archive, Grant County, Wisconsin severe weather history averages 11.5 recorded events a year. The busiest stretch on record is the 2010s, with 285 events logged in that decade alone. Roughly 100 events fall before 1990 and 725 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the Grant County, Wisconsin record is thunderstorm wind, responsible for 1 direct deaths. The costliest is tornado, with $27.9M in reported property damage. In total, 8 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in Grant County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Thunderstorm Wind | 331 | 1 | $6.3M | 74 | 1958–2026 |
| Hail | 252 | 0 | $3.9M | 3 | 1966–2026 |
| Flash Flood | 69 | 0 | $24.3M | 0 | 1997–2025 |
| Flood | 65 | 0 | $3.2M | 0 | 1998–2026 |
| Tornado | 55 | 0 | $27.9M | F3 | 1954–2024 |
| Heavy Rain | 29 | 0 | $500 | 0 | 2007–2023 |
| Funnel Cloud | 16 | 0 | $0 | 0 | 2007–2022 |
| Lightning | 8 | 1 | $71K | 0 | 2001–2020 |
Decade by decade
Grant County, Wisconsin severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
67 mapped tornado paths intersect this county: 59 touched down inside it and 8 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 1985-05-30 | EF3 | 2 | 27 | 34.0 mi | Crossed in |
| 2021-08-07 | EF3 | 0 | 0 | 9.4 mi | Touched down here |
| 1993-06-19 | EF3 | 0 | 0 | 14.0 mi | Crossed in |
| 1970-09-09 | EF3 | 0 | 0 | 4.7 mi | Crossed in |
| 2014-06-16 | EF2 | 0 | 5 | 3.8 mi | Touched down here |
| 2012-09-04 | EF2 | 0 | 0 | 0.7 mi | Touched down here |
| 1988-05-08 | EF2 | 0 | 0 | 10.0 mi | Touched down here |
| 1988-05-08 | EF2 | 0 | 0 | 7.5 mi | Touched down here |
| 1985-05-30 | EF2 | 0 | 0 | 16.0 mi | Touched down here |
| 1980-06-05 | EF2 | 0 | 0 | 70.2 mi | Crossed in |
Significant events
Deadliest events on record in Grant County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Jul 20, 2006 | Thunderstorm Wind | CASSVILLE | 1 | 0 | $1K |
| Aug 22, 2001 | Lightning | BLOOMINGTON | 1 | 0 | $0 |
| Jun 17, 2014 | Tornado | PLATTEVILLE | 0 | 5 | $20.5M |
| May 31, 1985 | Tornado | 0 | 2 | $2.5M | |
| Jun 27, 1973 | Tornado | 0 | 2 | $250K | |
| Jun 26, 1969 | Tornado | 0 | 2 | $25K | |
| Apr 6, 2005 | Lightning | MONTFORT | 0 | 1 | $0 |
| Jun 18, 1998 | Tornado | LANCASTER | 0 | 1 | $200K |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Very heavy rain produced flash flooding across the northeast part of Grant County. |In Boscobel, numerous houses became surrounded by water with evacuations needed, most streets were flooded and cars were under water. 650 homes were impacted by the flood waters with two dozen families displaced. County Roads M and S near Boscobel were impassable due to high water and several other county roads between Blue River and Fennimore were covered with water and impassable. Portions of County Road C southwest of Woodman were under water. The flooding washed out sections of State Highway 133 outside of Woodman and Blue River. Debris was washed down Glass Hollow and Dry Hollow Creeks where it became lodged across railroad bridges in Bagley producing flooding in the town. The railroad tracks through Woodman were washed out. Flooding debris blocked some roads around Patch Grove. 54 canoeists had to be rescued from the Wisconsin River because of rising water.
A major flash flood hit Grant County during the afternoon of June 12th impacting the communities of Lancaster, Potosi, Tennyson, Ellenboro, and other rural areas. Numerous rescues were performed from people trapped in cars, especially in the Potosi area where terrain enhanced the runoff from repeat thunderstorms. Several homes on Hippie Hollow Road in Potosi Township were destroyed along with damage to as many as 600 homes elsewhere in the region. Many highways and county roads suffered flood damage including major bridge and road infrastructure.
Flash flood waters backed up in town as debris blocked area bridges. The water was three to four feet deep in places and propane gas containers began floating on the Mississippi River. Property damage in town was extensive.
Context
Risk, population and federal disasters
Relatively Low
FEMA NRI risk rating
51,770
Population (ACS)
$201K
Median home value
20
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Apr 4, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
| Oct 7, 2017 | Severe Storm | SEVERE STORMS, STRAIGHT-LINE WINDS, FLOODING, LANDSLIDES, AND MUD | DR |
| Aug 8, 2013 | Severe Storm | SEVERE STORMS, FLOODING, AND MUDSLIDES | DR |
| Apr 5, 2011 | Snowstorm | SEVERE WINTER STORM AND SNOWSTORM | DR |
| Aug 11, 2010 | Severe Storm | SEVERE STORMS, TORNADOES, AND FLOODING | DR |
Within the county
Most affected places
- Burton 156
- Rockville 115
Quick answers
Frequently asked
How many severe weather events have been recorded in Grant County, Wisconsin?
825 events are on record between 1954 and 2026, causing 2 direct deaths and $65.6M in property damage.
What is the most common severe weather hazard in Grant County?
Thunderstorm Wind, with 331 recorded events — 40.1% of everything in the archive for this county.
How many tornadoes have crossed Grant County?
67 mapped tornado paths intersect the county boundary; 59 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover Grant County?
20 federal disaster declarations from FEMA include Grant County, each tied to a specific incident period.
How risky is Grant County compared with the rest of the country?
FEMA's National Risk Index rates Grant County as relatively low risk, placing it in the 61 percentile of its state for expected annual loss.
Where does the Grant County, Wisconsin severe weather history data come from?
Every figure is drawn from United States federal public-domain records: NOAA/NCEI Storm Events for the event archive, NOAA SPC SVRGIS for mapped tornado paths, FEMA for disaster declarations and risk ratings, and the U.S. Census for population context. Dates are shown in UTC and recent entries may still be revised by NOAA.
Nearby
Neighbouring counties
- Forest County 165
- Green County 412
- Green Lake County 223
- Fond du Lac County 440
- Iowa County 371
- Florence County 82
Cite this page
“Grant County, Wisconsin.” Severe Weather History. severeweatherhistory.com/county/wisconsin/grant-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.