County Hazards

States › Wisconsin › Walworth County

Walworth County, Wisconsin

Recorded hazard history: storm events since 1950, federal disaster declarations since 1953, flood insurance claims since 1978, and FEMA's risk index.

FIPS 55127 · 106,799 residents (2021) · 555 sq mi · dominant hazard Wind

Hail · 135Tornado · 45Flood · 35Wind · 388Winter · 225
1967-08-03: Hail1975-07-03: Hail1977-09-04: Hail1979-09-04: Hail1980-07-16: Hail1980-07-16: Hail1980-07-20: Hail1980-07-20: Hail1980-07-16: Hail1981-09-30: Hail1986-09-22: Hail1987-05-21: Hail1987-05-21: Hail1990-03-13: Hail1997-08-03: Hail1997-05-18: Hail1998-09-06: Hail1999-06-10: Hail1999-06-11: Hail2000-03-08: Hail2000-03-08: Hail2000-04-19: Hail2000-05-08: Hail2000-05-08: Hail2000-06-30: Hail2000-06-30: Hail2000-06-30: Hail2000-05-18: Hail2000-05-18: Hail2000-05-18: Hail2000-05-18: Hail2001-05-14: Hail2001-10-23: Hail2001-10-23: Hail2002-09-09: Hail2002-03-09: Hail2002-08-01: Hail2002-08-01: Hail2003-07-06: Hail2004-03-01: Hail2005-06-04: Hail2005-07-23: Hail2005-08-18: Hail2005-09-22: Hail2005-09-22: Hail2006-03-11: Hail2006-05-17: Hail2006-05-17: Hail2006-08-25: Hail2006-08-25: Hail2006-10-02: Hail2006-10-02: Hail2007-07-09: Hail2007-07-09: Hail2007-07-09: Hail2008-01-07: Hail2008-04-25: Hail2008-06-12: Hail2008-06-06: Hail2009-07-23: Hail2010-09-21: Hail2010-09-21: Hail2010-09-21: Hail2010-09-21: Hail2011-05-22: Hail2011-05-22: Hail2012-09-17: Hail2013-06-12: Hail2013-06-12: Hail2013-08-30: Hail2013-08-30: Hail2013-08-30: Hail2013-07-21: Hail2014-05-12: Hail2014-05-12: Hail2014-06-17: Hail2014-06-17: Hail2014-06-18: Hail2015-04-09: Hail2015-04-09: Hail2015-04-09: Hail2016-05-28: Hail2017-07-06: Hail2017-07-06: Hail2017-07-23: Hail2017-05-17: Hail2017-06-19: Hail2017-07-15: Hail2017-07-15: Hail2017-07-15: Hail2017-07-15: Hail2017-07-15: Hail2017-07-16: Hail2018-05-14: Hail2018-05-02: Hail2018-05-02: Hail2018-05-02: Hail2018-05-02: Hail2018-05-02: Hail2018-05-02: Hail2018-05-02: Hail2018-05-02: Hail2018-05-02: Hail2019-06-01: Hail2019-06-01: Hail2019-06-01: Hail2019-06-24: Hail2020-08-25: Hail2021-09-07: Hail2021-09-07: Hail2021-09-07: Hail2021-09-07: Hail2021-09-07: Hail2021-09-07: Hail2021-09-07: Hail2021-09-07: Hail1955-04-18: Tornado1957-04-19: Tornado1959-06-06: Tornado1961-09-22: Tornado1965-04-11: Tornado1965-04-11: Tornado1966-03-21: Tornado1967-06-10: Tornado1968-05-27: Tornado1970-05-09: Tornado1972-07-14: Tornado1972-09-28: Tornado1978-06-20: Tornado1978-08-15: Tornado1980-06-06: Tornado1988-07-16: Tornado1990-06-02: Tornado1991-07-07: Tornado1992-09-02: Tornado1997-07-18: Tornado2004-06-23: Tornado2008-01-07: Tornado2010-11-22: Tornado2015-08-18: Tornado2015-07-18: Tornado2018-08-20: Tornado2020-08-10: Tornado2022-10-12: Tornado2023-04-05: Tornado2023-03-31: Tornado2023-03-31: Tornado2023-03-31: Tornado2023-03-31: Tornado2023-03-31: Tornado2023-06-01: Tornado2024-05-07: Tornado2024-05-07: Tornado2024-06-22: Tornado2024-06-22: Tornado2026-04-17: Tornado2026-04-17: Tornado2026-04-17: Tornado2026-04-17: Tornado2026-04-14: Tornado2026-04-15: Tornado2006-03-13: Flood2007-08-22: Flood2007-08-19: Flood2008-06-08: Flood2008-06-12: Flood2009-06-19: Flood2013-06-26: Flood2017-07-12: Flood2017-07-12: Flood2018-02-20: Flood2019-09-12: Flood2019-09-13: Flood2020-04-29: Flood2020-08-10: Flood2023-04-04: Flood2025-08-18: Flood2025-06-18: Flood2026-06-11: Flood2026-04-15: Flood2026-04-15: Flood2026-06-11: Wind2026-04-17: Wind2026-04-14: Wind2026-04-14: Wind2026-04-02: Wind2026-04-02: Wind2025-07-11: Wind2025-06-03: Wind2025-03-14: Wind2025-03-14: Wind2025-03-14: Wind2024-08-06: Wind2024-08-06: Wind2024-08-06: Wind2024-08-06: Wind2024-07-14: Wind2024-05-24: Wind2024-05-21: Wind2024-05-21: Wind2024-05-07: Wind2024-05-07: Wind2024-05-07: Wind2024-05-07: Wind2024-03-04: Wind2024-03-04: Wind2023-08-24: Wind2023-08-24: Wind2023-08-24: Wind2023-07-28: Wind2023-07-28: Wind2023-07-28: Wind2023-07-26: Wind2022-11-05: Wind2022-10-12: Wind2022-10-12: Wind2022-09-25: Wind2022-07-24: Wind2021-08-10: Wind2021-07-07: Wind2020-11-10: Wind2020-11-10: Wind2020-11-10: Wind2020-11-10: Wind2020-11-10: Wind2020-11-10: Wind2020-08-25: Wind2020-08-10: Wind2020-07-09: Wind2020-07-09: Wind2019-09-10: Wind2019-08-07: Wind2019-06-30: Wind2019-06-27: Wind2019-06-27: Wind2018-05-02: Wind2017-06-29: Wind2017-06-29: Wind2017-05-17: Wind2017-05-17: Wind2017-04-20: Wind2017-03-07: Wind2016-09-07: Wind2016-07-21: Wind2015-08-17: Wind2015-08-02: Wind2015-08-02: Wind2015-07-18: Wind2015-07-13: Wind2015-06-22: Wind2015-05-26: Wind2015-04-29: Wind2014-06-30: Wind2014-06-30: Wind2014-06-17: Wind2014-06-17: Wind2013-08-30: Wind2013-08-30: Wind2013-08-30: Wind2013-08-22: Wind2013-07-21: Wind2013-07-21: Wind2013-07-21: Wind2013-05-30: Wind2012-09-04: Wind2012-07-30: Wind2012-07-24: Wind2012-07-24: Wind2012-05-20: Wind2011-08-02: Wind2011-08-02: Wind2011-07-23: Wind2011-07-11: Wind2011-07-11: Wind2011-07-11: Wind2011-06-21: Wind
Walworth County within Wisconsin. Dots: HailTornadoFloodWind event locations in the kept record. Boundaries: US Census Bureau.

NCEI notes that Storm Data is compiled from a variety of sources including the National Weather Service, other federal, state and local agencies, the media and the public; that property and crop damage figures are estimates; and that some events are recorded by NWS forecast zone rather than by county. FEMA notes that NFIP claim records are redacted and aggregated to protect the privacy of policyholders. NCEI storm records through 30 Jun 2026; OpenFEMA declarations refreshed 1 Oct 2026; NFIP claims as of 8 Sep 2026.

The NCEI record lists 1,038 events for Walworth County, Wisconsin, between 1950 and 2026; damaging wind account for the largest share.

That is 186.9 events per 100 square miles, above the Wisconsin figure of 85.6, and 97.2 per 10,000 residents against 78.6 statewide.

39 events fall in the 12 months to 30 Jun 2026. NCEI attributes 4 deaths and 43 injuries to events in the county, with property damage estimated at $30M and crop damage at $34M.

FEMA has designated the county in 13 federal disaster declarations since 1953; the most recent is Covid-19 Pandemic (major disaster, 4 Apr 2020).

National Flood Insurance Program policyholders in the county filed 46 claims since 1978, of which 33 were paid, totalling $647K (about $20K per paid claim). FEMA counts 112 residential flood policies in force.

FEMA's National Risk Index rates the county's overall risk as "Relatively Low" and its expected annual loss as "Relatively Low" ($40M a year across 18 hazards).

1 tropical storm or hurricane track in the HURDAT2 record passed within 100 miles of the county's centre at tropical-storm strength or more, 0 of them within 50 miles at hurricane strength.

39events, last 12 monthsto 30 Jun 2026
1,038events since 19504 deaths, 43 injuries recorded
13disaster declarationslast 4 Apr 2020
46NFIP flood claims$647K paid

Compared with Wisconsin and the United States

MeasureWalworth CountyWisconsinUS
Recorded events since 19501,03846,3621,977,440
Events per 100 square miles186.985.656.0
Events per 10,000 residents97.278.659.6
Events in the last 12 months391,62462,008
Deaths recorded by NCEI453026,435
Property damage (NCEI estimates)$30M$4.1B$575B
NFIP claims per 1,000 residents0.41.68.1
Average paid NFIP claim$20K$20K$43K
Claims per 100 policies in force, last 10 years23.223.416.1

County-recorded events plus zone-recorded events whose forecast zone is named for the county. State and US rows include events recorded only by forecast zone. Rates use 2021 Census population and land area.

Events by decade

Tornado: 3Wind: 1
Hail: 1Tornado: 6Wind: 8
Hail: 3Tornado: 5Wind: 6
Hail: 9Tornado: 2Wind: 34
Hail: 8Tornado: 4Flood: 7Wind: 93Winter: 10Heat: 7Cold: 7Lightning: 11Fog: 3Other: 4
Hail: 43Tornado: 2Flood: 14Wind: 105Winter: 66Heat: 15Cold: 10Drought: 12Lightning: 11Fog: 59Other: 5
Hail: 47Tornado: 4Flood: 6Wind: 84Winter: 90Heat: 14Cold: 11Drought: 6Fog: 14Other: 3
Hail: 24Tornado: 19Flood: 8Wind: 57Winter: 59Heat: 9Cold: 7Other: 2
41950s151960s141970s451980s1541990s3422000s2792010s1852020s
Recorded events in Walworth County by decade and hazard group. HailTornadoFloodWindWinterHeatColdDroughtLightningFogOther NCEI recorded only tornadoes, hail and thunderstorm wind before 1996.

Trend: 594 events in the 20 years to 2025 against 353 in the 20 years before. Reporting practice changed in 1996 and again with automated reports in the 2000s, so decade totals measure the record as much as the weather.

Events by type

Wind388
Winter225
Hail135
Fog76
Tornado45
Heat45
Flood35
Cold35
Lightning22
Drought18
Other14
HazardEventsDeathsShare of state's events
■ Wind388—2.6%detail
■ Winter22512.2%detail
■ Hail135—1.5%detail
■ Fog76—4.7%
■ Tornado45—2.5%detail
■ Heat4513.6%
■ Flood35—1.4%detail
■ Cold3522.0%
■ Lightning22—3.3%
■ Drought18—1.3%
■ Other14—1.4%

Hazard pages exist for hail, tornado, flood, wind and winter where the county has at least 10 recorded events. "Other" covers heavy rain, debris flow, dust, funnel clouds and similar reports.

Largest recorded events

DateEvent typeGroupMagnitudeProperty damageCrop damageDeathsInjuriesGeography
9 Jan 1996Cold/Wind ChillCold———1—Forecast zone
18 Jan 1996Cold/Wind ChillCold———1—Forecast zone
3 Jul 2012Excessive HeatHeat———1—Forecast zone
2 Mar 2017Winter WeatherWinter———1—Forecast zone
21 Jul 1998Thunderstorm WindWind100 mph$1.9M$105K—12County
6 Jul 2003LightningLightning————8County
13 Jun 2000Flash FloodFlood—$350K$300K—4County
26 Jun 1989Thunderstorm WindWind0 mph———3County
10 Jun 1999LightningLightning————3County
17 Jun 1996FloodFlood—$200K$24M——Forecast zone
20 Jul 1998Thunderstorm WindWind100 mph$1.5M——2County
31 Jul 2003LightningLightning————2County
21 Mar 1966TornadoTornadoF2$2.5M——1County
10 Nov 1998High WindWind—$700K$100K—1Forecast zone
18 Apr 1955TornadoTornadoF2$250K——1County
12 Jul 2017Flash FloodFlood—$10M$30K——County
22 Sep 1961TornadoTornadoF2$25K——1County
10 Jun 1999Thunderstorm WindWind—$10K——1County
7 Jul 1991Thunderstorm WindWind0 mph———1County
19 Sep 1997LightningLightning————1County

Ranked by deaths, then injuries, then NCEI's damage estimate. Deaths and injuries are NCEI counts (direct plus indirect); no personal details are recorded here.

Federal disaster declarations

DeclaredNumberTypeIncidentTitlePrograms
4 Apr 2020DR-4520Major disasterBiologicalCovid-19 PandemicIndividual assistance, Public assistance
13 Mar 2020EM-3454EmergencyBiologicalCovid-19Public assistance
5 Apr 2011DR-1966Major disasterSnowstormSevere Winter Storm And SnowstormPublic assistance
14 Jun 2008DR-1768Major disasterSevere StormSevere Storms, Tornadoes, And FloodingIndividual assistance, Public assistance
19 Mar 2008EM-3285EmergencySnowstormRecord Snow And Near Record SnowPublic assistance
13 Sep 2005EM-3249EmergencyHurricaneHurricane Katrina EvacuationPublic assistance
18 Jun 2004DR-1526Major disasterSevere StormSevere Storms And FloodingIndividual assistance
24 Jan 2001EM-3163EmergencySnowstormSnowPublic assistance
24 Jun 2000DR-1332Major disasterSevere StormSevere Storms, Tornadoes, And FloodingIndividual assistance, Public assistance
17 Jun 1976EM-3014EmergencyDroughtDroughtPublic assistance
23 Mar 1976DR-496Major disasterFloodSevere Storms, Icing, Wind & FloodingIndividual assistance, Public assistance
27 Apr 1973DR-376Major disasterFloodSevere Storms & FloodingIndividual assistance, Public assistance
21 Apr 1965DR-192Major disasterTornadoTornadoes, Severe Storms & FloodingIndividual assistance, Public assistance

Declarations in which FEMA designated this county, from the OpenFEMA Disaster Declarations Summaries (v2). DR: major disaster; EM: emergency; FM: fire management assistance. Programs show whether individual or public assistance was made available.

Flood insurance claims

197820022026
NFIP claims by year of loss in Walworth County, 1978 to 2026 (hover for the amount paid).
Claims since 197846
Paid claims33
Total paid$647K
Average paid claim$20K
Repetitive-loss properties50 severe
Residential policies in force1120.3% of 35,658 structures
Year of lossClaimsPaid claimsAmount paidAverage paid
202644$95,593$23,898
20201110$187,164$18,716
201953$14,818$4,939
201811$129,090$129,090
201755$175,691$35,138
201510$0—
201365$29,709$5,942
201120$0—
201021$1,071$1,071
200911$10,233$10,233
200811$2,499$2,499
200710$0—
199410$0—
198610$0—
198311$448$448
198021$328$328
197910$0—

OpenFEMA NFIP claims (v3, as of 8 Sep 2026), aggregated by year of loss; amounts are building, contents and increased-cost-of-compliance payments as recorded. Repetitive-loss counts from the NFIP Multiple Loss Properties file (2 Aug 2026); policies in force from the NFIP Residential Penetration Rates file (3 Aug 2026).

National Risk Index

Overall riskRelatively Lowscore 74.8 of 100
Expected annual loss$40MRelatively Low
Social vulnerabilityRelatively Low
Community resilienceVery High
Hazard (NRI)Risk ratingExpected annual loss
Inland floodingRelatively Moderate$17,582,356
TornadoRelatively Moderate$7,489,906
Cold waveRelatively Moderate$7,038,628
HailRelatively High$3,319,333
Strong windRelatively Moderate$1,607,996
Heat waveRelatively Low$1,288,494
LightningRelatively Moderate$710,832
EarthquakeVery Low$358,083
DroughtRelatively Low$108,746
Winter weatherRelatively Low$84,871
Ice stormRelatively Low$77,920
WildfireVery Low$12,707
LandslideRelatively Low$4,592
HurricaneVery Low$3,410

FEMA National Risk Index, December 2025 release. Ratings are FEMA's relative comparison of counties; expected annual loss is FEMA's modelled estimate of average yearly building, population and agriculture loss. See how to read the NRI.

Hurricane and tropical storm passes

Tracks within 100 miles1
Tracks within 50 miles1
Hurricane strength within 50 miles0
StormYearClosest approachMax wind while within 100 mi
Unnamed Atlantic storm19006 mi58 mph

HURDAT2 best-track positions at tropical-storm strength (34 kt) or more, measured from the county's Census centre point; through the 2025 season. Distance from a track is not the same as the extent of the storm's wind, rain or surge.

ZIP codes with flood claims

ZIP codes whose NFIP claims carry this county's code, with the number of claims. Five or more claims are needed for a ZIP page to be indexed.

Questions and answers

How often does it hail in Walworth County, WI?

NCEI records 135 hail events in Walworth County since 1950, in 41 different years; that is about 1.8 recorded events a year. 18 reports were golf-ball size (1.75 in) or larger.

Has Walworth County had a tornado?

Yes. NCEI records 45 tornadoes in Walworth County since 1950, 6 of them rated (E)F2 or stronger. Tornado deaths recorded: 0.

When was the last federal disaster declaration for Walworth County?

4 Apr 2020: Covid-19 Pandemic, a major disaster declaration for biological. The county appears in 13 declarations since 1953.

How many flood insurance claims have been filed in Walworth County, and how much was paid?

46 NFIP claims since 1978, 33 of them paid, for $647K in total. FEMA publishes these figures redacted and aggregated; individual properties are not identified.

Is Walworth County in the National Risk Index's high-risk band?

FEMA's National Risk Index (December 2025) rates the county "Relatively Low" for overall risk, "Relatively Low" for expected annual loss, "Relatively Low" for social vulnerability and "Very High" for community resilience. These ratings are FEMA's relative comparison across all US counties.

How does Walworth County compare with the rest of Wisconsin?

186.9 recorded events per 100 square miles against 85.6 statewide, and 0.4 NFIP claims per 1,000 residents against 1.6. The comparison table on this page shows each measure beside the state and national figures.

Provenance

Storm events: NOAA NCEI Storm Events Database, yearly details files through 30 Jun 2026 (public domain). Declarations: OpenFEMA DisasterDeclarationsSummaries v2, refreshed 1 Oct 2026. Flood claims: OpenFEMA NfipClaims v3 as of 8 Sep 2026; NfipMultipleLossProperties v1 (2 Aug 2026); NfipResidentialPenetrationRates v1 (3 Aug 2026). Risk index: FEMA National Risk Index, December 2025. Hurricane tracks: NHC HURDAT2 through 2025. Population and area: US Census Bureau, 2021 vintage. Built 1 Oct 2026; see the methodology and corrections pages. Hazard hubs: Hail · Tornado · Flood · Wind · Winter.