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Walworth County, Wisconsin

Natural disaster risk, federal disaster history and flood insurance facts.

Relatively Low overall risk
20th of 72highest risk in Wisconsin
$40Mexpected losses a year
11federal declarations
1 in 333homes with flood insurance
Photo: U.S. Geological Survey, public domain

Walworth County, Wisconsin has a relatively low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 75% of US counties. It ranks 20th of 72 counties in Wisconsin. The costliest hazards here are inland flooding, tornadoes and cold waves. FEMA estimates about $40 million a year in expected losses, or roughly $373 per resident. Since 1965 it has been included in 11 federal disaster or emergency declarations for natural events (7 major disasters). The most recent was in April 2011 (severe winter storm and snowstorm). Fewer than 1 in 100 homes here carry federal flood insurance (112 policies). Since 1978, federal flood insurance has paid about $647,000 on 46 claims here.

FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.

Top risks in Walworth County

$17.6 million a yearExpected losses. Damaging events about once a year.
  • Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
  • Price a flood policy now. Most new federal policies take 30 days to start.

Tornado

Moderate
$7.5 million a yearExpected losses. Damaging events about once every 2 years.
  • Pick a shelter spot: a basement, or an inside room on the lowest floor with no windows.
  • Turn on emergency alerts on your phone and keep a weather radio.

Cold wave

Moderate
$7 million a yearExpected losses. Damaging events about 5 times a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.
HazardRatingScoreExpected loss a year
Inland floodingModerate73.2
$18M
TornadoModerate88.2
$7M
Cold waveModerate88.0
$7M
HailHigh94.8
$3M
Strong windModerate81.1
$2M
Heat waveLow74.0
$1M
LightningModerate75.4
$711K
EarthquakeVery Low52.1
$358K
DroughtLow43.7
$109K
Winter weatherLow53.5
$85K
Ice stormLow44.6
$78K
WildfireVery Low25.3
$13K
LandslideLow65.2
$5K
HurricaneVery Low12.6
$3K

Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is relatively low and community resilience is very high in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

Federal declarations for natural events that included Walworth County. 2020s bar runs to November 2026.

By type

Severe Storm3
Snowstorm3
Flood2
Tornado1
Drought1
Hurricane1

Most recent

Apr 5, 2011Severe Winter Storm and SnowstormMajor disaster
Jun 14, 2008Severe Storms, Tornadoes, and FloodingMajor disaster
Mar 19, 2008Record Snow and Near Record SnowEmergency
Sep 13, 2005Hurricane Katrina EvacuationEmergency
Jun 18, 2004Severe Storms and FloodingMajor disaster
Jan 24, 2001SnowEmergency
Jun 24, 2000Severe Storms, Tornadoes, and FloodingMajor disaster
Jun 17, 1976DroughtEmergency
Mar 23, 1976Severe Storms, Icing, Wind & FloodingMajor disaster
Apr 27, 1973Severe Storms & FloodingMajor disaster
Show all 11
Apr 21, 1965Tornadoes, Severe Storms & FloodingMajor disaster

Wisconsin also had 8 statewide declarations that did not name single counties.

Storm history since 1955

Tornado risk by county ›

The National Weather Service has logged 572 storm reports in Walworth County since 1955, with 3 deaths and 52 injuries and about $35.5 million in reported damage. The strongest on record here was an F2 tornado on March 21, 1966.

45tornadoes
135hail reports, largest 2.5 inches
331damaging thunderstorm winds
31floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Mar 21, 1966F2–1 / 0
Apr 18, 1955F2–1 / 0
Apr 19, 1957F2–0 / 0
Sep 28, 1972F2–0 / 0
Jun 6, 1980F2–0 / 0

Most damaging storms

DateTypeNearDamage
Jul 12, 2017Flash FloodLa Grange$10M
Jun 12, 2008Flash FloodDelavan$5M
Mar 21, 1966Tornado–$3M
Jul 21, 1998Thunderstorm WindElkhorn$2M
Jul 20, 1998Thunderstorm WindLake Geneva$2M
Jun 13, 2000Flash FloodWalworth$1M

Source: NOAA Storm Events Database, county-based reports through Jul 3, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.

Flood insurance in Walworth County

Check your address flood zone ›
0.3%of homes have federal flood insurance (112 policies)
38.5%of homes in mapped high-risk flood zones are insured
$646,644paid on 46 flood claims since 1978
2020costliest year, with $187,164 paid

National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.

Homes in Walworth County

$302,700median home value (Wisconsin $266,500, US $332,700)
1977median year homes were built (Wisconsin 1975, US 1980)
54%of homes built before 1980, before many modern wind, quake and flood building rules
2.4%of homes are mobile homes, which are the least safe in tornadoes and high winds

Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 54,124 housing units.

Compare in Wisconsin

All 72 ›
Largest countiesOverall riskTop hazard
Milwaukee CountyHighCold wave
Dane CountyModerateInland flooding
Waukesha CountyModerateInland flooding
Brown CountyModerateInland flooding
Racine CountyModerateInland flooding
Outagamie CountyLowInland flooding
Winnebago CountyModerateInland flooding
Kenosha CountyModerateCold wave

Neighboring counties

CountyOverall riskDeclarations
Waukesha CountyModerate17
McHenry County, ILModerate14
Racine CountyModerate15
Kenosha CountyModerate14
Rock CountyModerate14
Jefferson CountyLow12
Boone County, ILLow9

Common questions about Walworth County

What is the biggest natural hazard in Walworth County?

Inland flooding has the highest expected yearly losses in Walworth County, about $17.6 million a year in FEMA's estimate. Tornado is second at $7.5 million.

How many federal disasters has Walworth County had?

Walworth County has been included in 11 federal disaster or emergency declarations for natural events since 1965, including 7 major disasters. The most recent was Severe Winter Storm and Snowstorm in April 2011.

Is Walworth County a high-risk place to live?

Its overall rating is Relatively Low, 20th highest of 72 in Wisconsin. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.

Do I need flood insurance in Walworth County?

Standard home insurance does not cover flooding. About 1 in 333 homes in Walworth County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.

How many tornadoes has Walworth County had?

NOAA records list 45 tornadoes in Walworth County since 1950. The strongest was an F2 tornado on March 21, 1966. The weather service has also logged 135 hail reports and 31 floods here.

Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.