Walworth County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Walworth County: 0.
2. Weak tornadoes were under-recorded before Doppler radar coverage became national in the early 1990s, so earlier decades read low. Ratings use the Fujita scale before February 2007 and the Enhanced Fujita scale after.

Storm Prediction Center severe weather database, 1950 to 2025.

Smoke overhead

1. A smoke day is a date on which a smoke plume traced by NOAA Hazard Mapping System analysts from satellite imagery covered this place's point (the county's population centre or the city centre). Counts here are of medium or heavy smoke. Since 2018 analysts have often drawn light smoke as one area over most of the continent, so light-smoke counts are not comparable from year to year. The plumes show smoke anywhere in the air above, not air quality at the ground, and smoke hidden by cloud is missed.

NOAA Hazard Mapping System smoke analysis, 2011 to 2026, retrieved October 30, 2026.

Claims by ZIP code

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.

1. The Palmer Drought Severity Index is computed by NOAA each month from the county's average temperature and precipitation, relative to the county's own climate. Zero is normal; -3 or lower is severe drought and -4 or lower extreme drought. It describes the long-term balance of moisture, not water supply or crop losses.

NOAA NCEI nClimDiv county Palmer Drought Severity Index, 1895 to September 2026, issued October 6, 2026.

1. Earthquakes of magnitude 2.5 or more in the USGS Comprehensive Catalog since 1900. Within 50 miles means the epicentre lies within 50 miles of the county boundary (or inside the county).
2. Small earthquakes were under-recorded before the modern seismic networks of the 1970s and are still missed in remote areas, so early decades read low. Magnitudes are as the catalogue reports them and mix scales (moment, local and body-wave).

USGS ANSS Comprehensive Earthquake Catalog, 1900 to present, retrieved October 30, 2026.

More event types since 1996

Costliest events since 1996

1. Jul 12, 2017Flash Flood$10.0 million
   National Weather Service narrative

   Various road closures over the eastern half of Walworth County due to the flash flooding of creeks or the pooling of water in low spots after 3.50-8.00 inches of rain. Walworth County declared an emergency. Road closures near Springfield, Abells Corners, south and east of East Troy. Also, widespread flooding and road closures in and around Elkhorn after 3.26 inches of rain in an hour. The water flowed into some businesses and the Huber Dorm. Some cars were stranded in deep water. Residents of the Bud Motors Trailer Park in the Town of Lyons evacuated due to flooding from the White River. Also in Lyons, the Ore Creek flooded and destroyed a portion of the foundation of a home. Ten…

2. Jul 21, 1998Thunderstorm Wind$1.9 million
   National Weather Service narrative

   Scattered thunderstorms developed in an unstable atmosphere over southcentral Wisconsin in the early afternoon hours. These storms quickly became severe and merged over Walworth County. Hurricane-force winds were generated over the north side of Elkhorn (Walworth Co.); and the resultant wind damage strongly suggests that winds gusts peaked in the 100 to 110 mph range. Officials in Elkhorn declared a state of emergency and asked for extra help with the cleanup, thanks to hundreds of downed trees and many power lines. Several Elkhorn downtown office buildings suffered some minor damage, while 6 buildings on the north side along Highway 67 had considerable damage (3-minor, 1 major,…

3. Jul 20, 1998Thunderstorm Wind$1.5 million
   National Weather Service narrative

   Frontal induced severe thunderstorms downed trees and power lines over much of south-central and southeast Wisconsin during the evening hours. Hardest hit was the Lake Geneva (Walworth Co.) area where downburst winds leveled hundreds of large trees, several street signs, and a large quantity of commercial signs. A dozen vehicles were damaged or totaled and 2 homes sustained significant damage. A 100 mph wind was recorded at the Grand Geneva Airport and 2 people were injured (one in a moving vehicle). Local officials consider this to be the worst storm in 58 years. In Monroe (Green Co.), the powerful thunderstorm winds also damaged 6 vehicles and 2 homes. Elsewhere, hail, high…

4. Nov 22, 2010Tornado$1.0 million
   National Weather Service narrative

   A tornado moved into extreme south-central Walworth County from Illinois about 5,100 feet west of the intersection of Alden Road and State Line Road, and quickly intensified to EF-1 rating. It moved northeast for over 5 miles before dissipating about 1,700 feet southeast of the intersection of County Road BB and Zenda Road. Five homes sustained damage, with two homes severely damaged. The tornado crossed CTH B where it dog-legs east of Swamp Angel Rd. Collectively, three sheds and two barns were damaged, with one of the barns flattened. Eight wooden power poles were also snapped, along with numerous trees and fences. On one farm, 4 cows, and several chickens and turkeys were…

5. Jun 13, 2000Flash Flood$850,000
   National Weather Service narrative

   Flash flooding and scattered severe thunderstorms struck parts of south-central and southeast Wisconsin during the afternoon and evening hours. Several clusters of showers and thunderstorms moved east/northeast at 35 to 40 mph across the area. Synoptically, a warm front stalled over northern Illinois with an axis of instability extending north into southern Wisconsin. A short-wave trough aloft moved east through the region. South of the surface front the dewpoints were in the 70s. Here is a break down by county:Walworth Co: this county was hit hard with two periods of heavy rains which resulted in flash flooding. Lake Petite, just south of Fontana, overflowed into a retention…

6. Jul 11, 2011Thunderstorm Wind$800,000
   National Weather Service narrative

   Law enforcement officials reported trees and power lines down in a 5-mile wide swath from northeast of Tibbets to east of Elkhorn due to damaging thunderstorm wind gusts estimated at 60 knots (69 mph). Corn crops were also blown down by the damaging winds. Two county salt storage sheds off of County Highway NN in Elkhorn were also severely damaged by the thunderstorm gusts.Winds caused the paneling of one shed to collapse into the structure. The roof of the other shed was lifted from it's foundation, damaging electrical utilities attached to it and adjacent buildings before settling back down. Officials estimate it will cost $800,000 to repair the sheds. Trees also toppled over…

7. Nov 10, 1998High Wind, Walworth$700,000
   National Weather Service narrative

   Screaming high winds raked all of southcentral and southeast Wisconsin's counties for about 17 hours, resulting in widespread damage to thousands of trees, homes, businesses, power poles, power lines, street lights, road signs, billboards, fences, flagpoles, barns, sheds, crops, boats, cars, trucks, campers, trains, airport hangers, and airplanes. Four people were killed, and 14 people were injured. Estimated monetary damages were $10.31 million to property and $1.625 million to crops. The sustained southwesterly winds of 30 to 40 mph gusted to 60 to 70 mph, with isolated locations having gusts to around 80 mph. These relentless winds eventually caused about 125,000 customers to…

8. Jun 12, 2008Flash Flood$526,000
   National Weather Service narrative

   Heavy rains resulted in flash flooding across mostly the northeast part of Walworth County. Water depths on road surfaces reached 3 feet or more and there were gravel washouts. Soem roads were closed. Some farm fields remained flooded into early July. The breakdown for residential home losses were: 23 with minor damage (total of $183 thousand for home losses). There were no business losses. Crop losses were estimated at $4.254 million. Public sector damage was about $342.6 thousand. Some roads and bridges sustained damage.

9. Jun 1, 2004Flood, Walworth$500,000
   National Weather Service narrative

   Scattered to widespread heavy rains across south-central and southeast Wisconsin during the period of June 9-12, 2004 kept many rivers and streams at or above flood stage for a good part, or most of the month. Monthly rainfall totals generally ranged from 4 to 7 inches across south-central and southeast Wisconsin, with some scattered spots in Sauk, Columbia, Dodge, Walworth, Racine, and Kenosha Counties picking up 7 to 9.5 inches, or 50 to 100% above normal. In some cases, stretches of some rivers actually went above flood stage in May, 2004. Refer to flood and flash flood events in May, 2004, for additional information. During June, 2004, the high water levels kept much of the…

10. Jul 3, 2026Thunderstorm Wind$500,000
    National Weather Service narrative

    Widespread straight-line wind damage occurred from just south of Darien in the Sharon Township through Delavan Lake to Como. These strong winds also swept across Geneva Lake where a 25 foot boat with 10 people on board capsized and sank when high waves impacted the boat. 3 children drowned. Witnesses stated the high winds during the storm came in three distinct bursts. Several other boats also capsized on the lake. 5-10 barns were destroyed or heavily damaged and about 40 homes sustained some damage mostly from fallen trees. Three 20 foot by 90 foot empty silos collapsed and fell on 4 motorists that were seeking shelter from the storm. 2 of them were seriously injured. Hundreds of…

1. Storm Events records before 1996 cover only tornadoes, thunderstorm wind and hail. Damage figures are as reported by the National Weather Service at the time, not adjusted for inflation.

NOAA NCEI Storm Events Database, 1950 to 2026, issued October 26, 2026.

All-time high

105°F2 times, most recently Jul 15, 1995

All-time low

−27°F6 times, most recently Feb 1, 2019

Warmest night

79°FJul 27, 1955

Coldest day

−17°FJan 19, 1994

Wettest day

5.45 inAug 15, 2023

Snowiest day

17.0 inFeb 2, 2011

Hottest year

1998mean 49.4°F

Coldest year

2014mean 42.8°F

Wettest year

201950.50 in

Driest year

198918.40 in

Snowiest season

74.7 in2007-08

Station Burlington Wwtp (USC00471205), 777 ft elevation, 14.6 miles from the population centre. Daily records from 1951 to October 23, 2026; 98.1% of days in the last 30 years are complete. Records at a single station can differ from a city’s official threaded record, which may combine several stations.

NOAA NCEI Global Historical Climatology Network Daily.

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA Disaster Declarations Summaries, retrieved October 30, 2026. Statewide declarations are not listed.

Neighbouring counties

• Tornadoes NOAA Storm Prediction Center severe weather database, through 2025.
• Tropical cyclones NOAA National Hurricane Center HURDAT2 (Atlantic; Northeast and Central Pacific), through 2025.
• Wildfire USGS/USFS Monitoring Trends in Burn Severity, through 2026.
• Storm events NOAA NCEI Storm Events Database, through 2026.
• Flood insurance OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026.
• Declarations OpenFEMA Disaster Declarations Summaries v2, retrieved October 30, 2026.
• Weather records NOAA NCEI Global Historical Climatology Network Daily, station USC00471205.
• River crests NOAA National Weather Service, National Water Prediction Service river gauges, retrieved October 30, 2026.
• Drought NOAA NCEI nClimDiv county Palmer Drought Severity Index, through September 2026.
• Smoke NOAA NESDIS Hazard Mapping System smoke analysis, retrieved October 30, 2026.
• Earthquakes USGS ANSS Comprehensive Earthquake Catalog (ComCat), retrieved October 30, 2026.

Joins, thresholds and known limits are set out in the methodology. Found an error? Report it. Page built October 30, 2026.