Walworth County, Wisconsin: hazard history
What federal records show has already happened here: disaster declarations, storms, and flood insurance claims. This is a record of the past. It is not a forecast and not a hazard score.
At a glance
What this means
- The event NOAA recorded most often here is Thunderstorm Wind, with 244 records.
- The costliest single record is Flash Flood in 2017: $10.0M in property damage, in the dollars of that year.
- The deadliest record is Cold/Wind Chill in 1996, with 1 death.
- FEMA has declared 13 disasters that named this county, most often for severe storm.
- The worst year for flood insurance claims was 2020, with 11 claims.
What this can't tell you
- What happens next. Past events do not set the odds of the next one.
- Anything before 1996 from NOAA. That is when NOAA began recording every event type; earlier files hold only tornado, hail and wind, so they are left out on purpose.
- Today's cost. Damage and payments are in the dollars of the year they happened.
- A flood rate. NFIP counts claims but not how many homes were insured, and many flooded homes carry no flood insurance.
- Earthquakes, wildfire perimeters or radar-detected hail. Those records are not tied to counties.
Federal disaster declarations (FEMA)
FEMA declared 13 disasters that named Walworth County between 1965 and 2020.
| Incident type | Disasters | Most recent |
|---|---|---|
| Severe Storm | 3 | 2008 |
| Snowstorm | 3 | 2011 |
| Biological | 2 | 2020 |
| Flood | 2 | 1976 |
| Drought | 1 | 1976 |
| Hurricane | 1 | 2005 |
| Tornado | 1 | 1965 |
Most recent declarations
- EM-3454 2020 · Biological · Covid-19
- DR-4520 2020 · Biological · Covid-19 Pandemic
- DR-1966 2011 · Snowstorm · Severe Winter Storm And Snowstorm
- DR-1768 2008 · Severe Storm · Severe Storms, Tornadoes, And Flooding
- EM-3285 2008 · Snowstorm · Record Snow And Near Record Snow
- EM-3249 2005 · Hurricane · Hurricane Katrina Evacuation
- DR-1526 2004 · Severe Storm · Severe Storms And Flooding
- EM-3163 2000 · Snowstorm · Snow
- DR-1332 2000 · Severe Storm · Severe Storms, Tornadoes, And Flooding
- EM-3014 1976 · Drought · Drought
Not counted above: 5 statewide declarations, which covered every county in Wisconsin. A declaration is a decision to send federal help, not a measure of how bad an event was. Records run from 1953. Source: FEMA OpenFEMA Disaster Declarations Summaries.
Storms recorded by NOAA, by type
| Event type | Records | Deaths | Injuries | Property damage |
|---|---|---|---|---|
| Thunderstorm Wind | 244 | 0 | 16 | $7.2M |
| Winter Weather | 158 | 1 | 0 | $6K |
| Hail | 119 | 0 | 0 | $1K |
| Dense Fog | 76 | 0 | 0 | $0 |
| Strong Wind | 49 | 0 | 0 | $250K |
| Winter Storm | 49 | 0 | 0 | $30K |
| Heat | 36 | 0 | 0 | $0 |
| Cold/Wind Chill | 27 | 2 | 0 | $2K |
| Tornado | 26 | 0 | 0 | $3.3M |
| Lightning | 22 | 0 | 14 | $487K |
| Drought | 18 | 0 | 0 | $0 |
| Flash Flood | 18 | 0 | 4 | $12.7M |
| Flood | 16 | 0 | 0 | $915K |
| High Wind | 13 | 0 | 1 | $969K |
| Extreme Cold/Wind Chill | 8 | 0 | 0 | $0 |
| Funnel Cloud | 8 | 0 | 0 | $0 |
| Heavy Snow | 8 | 0 | 0 | $0 |
| Blizzard | 7 | 0 | 0 | $0 |
| Excessive Heat | 7 | 1 | 0 | $0 |
| Heavy Rain | 6 | 0 | 0 | $4K |
| Ice Storm | 3 | 0 | 0 | $0 |
Records start in 1996. Damage is NOAA's estimate at the time, in nominal dollars, and is often rounded; it is not insurance claims data. A storm that crossed two NOAA zones in this county is recorded, and counted, once per zone. A storm filed against a forecast zone is counted in every county that zone covers, with the whole storm's damage; do not add these figures across counties.
Year by year
NOAA storm event records in Walworth County each year. The busiest year was 2008, with 55 records.
Show the numbers for every year
| Year | Records | Deaths | Property damage |
|---|---|---|---|
| 1996 | 22 | 2 | $781K |
| 1997 | 33 | 0 | $674K |
| 1998 | 31 | 0 | $4.4M |
| 1999 | 30 | 0 | $183K |
| 2000 | 37 | 0 | $1.6M |
| 2001 | 34 | 0 | $45K |
| 2002 | 28 | 0 | $80K |
| 2003 | 17 | 0 | $3K |
| 2004 | 24 | 0 | $609K |
| 2005 | 40 | 0 | $302K |
| 2006 | 37 | 0 | $137K |
| 2007 | 37 | 0 | $356K |
| 2008 | 55 | 0 | $1.2M |
| 2009 | 33 | 0 | $100K |
| 2010 | 29 | 0 | $1.1M |
| 2011 | 30 | 0 | $942K |
| 2012 | 35 | 1 | $28K |
| 2013 | 34 | 0 | $222K |
| 2014 | 26 | 0 | $40K |
| 2015 | 23 | 0 | $219K |
| 2016 | 16 | 0 | $49K |
| 2017 | 29 | 1 | $10.2M |
| 2018 | 30 | 0 | $23K |
| 2019 | 27 | 0 | $85K |
| 2020 | 24 | 0 | $200K |
| 2021 | 24 | 0 | $56K |
| 2022 | 27 | 0 | $59K |
| 2023 | 25 | 0 | $778K |
| 2024 | 28 | 0 | $512K |
| 2025 | 25 | 0 | $18K |
| 2026 | 28 | 0 | $888K |
Years with no record are left out of the table, not shown as zero.
Notable events
Costliest records
- Flash Flood · Jul 12, 2017$10.0MNOAA name: Walworth County · NOAA record 711659
- Thunderstorm Wind · Jul 21, 1998$1.9MNOAA name: Walworth County · 12 injuries · NOAA record 5662548
- Thunderstorm Wind · Jul 20, 1998$1.5MNOAA name: Walworth County · 2 injuries · NOAA record 5662370
- Tornado · Nov 22, 2010$1.0MNOAA name: Walworth County · NOAA record 263688
- Flash Flood · Jun 13, 2000$850KNOAA name: Walworth County · NOAA record 5153190
Deadliest records
- Cold/Wind Chill · Jan 9, 19961 deathNOAA name: NWS forecast zone · NOAA record 5538088
- Cold/Wind Chill · Jan 18, 19961 deathNOAA name: NWS forecast zone · NOAA record 5538297
- Excessive Heat · Jul 3, 20121 deathNOAA name: NWS forecast zone · NOAA record 404573
- Winter Weather · Mar 2, 20171 deathNOAA name: NWS forecast zone · NOAA record 672916
Each line is one NOAA record, linked to its page at NOAA. One large storm can appear more than once if NOAA recorded it in several zones of this county. Dollars are nominal.
Flood insurance claims (NFIP)
The National Flood Insurance Program paid $551K on 41 claims in Walworth County from 1979 to 2020.
| Year | Claims | Paid |
|---|---|---|
| 2020 | 11 | $187K |
| 2013 | 6 | $30K |
| 2019 | 5 | $15K |
| 2017 | 5 | $176K |
| 2011 | 2 | $0 |
A count of claims, not a rate: NFIP publishes no count of insured homes beside it, and most flood damage is uninsured. Nominal dollars. Records run from 1978 to 2024; claims filed without a county code are not on any county page. Source: FEMA OpenFEMA FIMA NFIP Redacted Claims.
Hazard vulnerability analysis: the probability column for a facility in Walworth County
A hazard vulnerability analysis rates each hazard for probability, impact, preparedness and response. Probability is the one column the county’s federal record can fill — NCEI storm events from 1996 to 2026 and FEMA declarations naming the county — and this is what it says for a facility here, on the 0–3 scale of the all-hazards structure surveyors expect. The other six columns are the facility’s own judgment about its building, and Calchis leaves them blank.
| Hazard | Prob. | Basis, from the county record |
|---|---|---|
| Severe Thunderstorm | 3 | 385 NCEI events over 31 years (12.42/yr). 3 federal disaster declarations naming the county. |
| Flood, External | 3 | 40 NCEI events over 31 years (1.29/yr). 2 federal disaster declarations naming the county. |
| Snow Fall / Blizzard / Ice Storm | 3 | 225 NCEI events over 31 years (7.26/yr). 3 federal disaster declarations naming the county. |
| Temperature Extremes | 3 | 78 NCEI events over 31 years (2.52/yr). No federal disaster declaration of this kind has named the county. |
| High Wind (non-convective) | 3 | 62 NCEI events over 31 years (2.00/yr). No federal disaster declaration of this kind has named the county. |
| Hurricane / Tropical Storm | 2 | No events of this kind on the county's NCEI record over 31 years. 1 federal disaster declaration naming the county. |
| Tornado | 2 | 26 NCEI events over 31 years (0.84/yr). 1 federal disaster declaration naming the county. |
| Drought | 2 | 18 NCEI events over 31 years (0.58/yr). 1 federal disaster declaration naming the county. |
| Epidemic | 2 | 2 federal disaster declarations naming the county. |
| Wild Fire | 1 | No events of this kind on the county's NCEI record over 31 years. No federal disaster declaration of this kind has named the county. |
| Earthquake | 1 | No federal disaster declaration of this kind has named the county. |
| Landslide | 1 | No events of this kind on the county's NCEI record over 31 years. No federal disaster declaration of this kind has named the county. |
| Tidal Wave / Tsunami | 1 | No events of this kind on the county's NCEI record over 31 years. No federal disaster declaration of this kind has named the county. |
| Volcano | 1 | No events of this kind on the county's NCEI record over 31 years. No federal disaster declaration of this kind has named the county. |
| Dam Inundation | 1 | No federal disaster declaration of this kind has named the county. |
A dash means the record does not speak to that hazard; it is not a zero. Whether a finished document satisfies the CMS Emergency Preparedness Rule is the facility’s finding and its surveyor’s. Complete the HVA for a facility in Walworth County — the technological, human and hazardous-materials rows, the six facility columns, the approval and the printed document — or read the sample analysis on that page first.
How this page was made
- Every figure is counted from public federal records held by Calchis: NOAA NCEI Storm Events, FEMA OpenFEMA Disaster Declarations, and FEMA NFIP claims. Nothing is modeled or estimated.
- NOAA files some events against a county and others against an NWS forecast zone, and publishes a code for both. Records are counted as Walworth County by that code — county records by the county's own FIPS code, zone records through the National Weather Service's published list of which counties each zone covers. No name matching is involved. Of 918 records, 457 were filed against this county and 461 against a forecast zone covering it. A zone storm is counted in every county its zone covers, and its damage figure is the whole storm's, not this county's share — NOAA does not publish that split. So these figures describe this county; they must not be added up across counties.
- Counts last rebuilt from the source records on Sep 15, 2026.
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Recorded history from federal public records. Not a hazard score, a risk score, or a forecast, and not a substitute for professional actuarial or emergency-management assessment. Decision-support intelligence — not a primary alerting or dispatch system. Verify against official sources.