NHC HURDAT2 · SPC Tornado Database
Hurricanes and Tornadoes That Hit Delavan, WI
Every tropical system within 75 miles since 1851 and every tornado within 25 miles since 1950.
Data: NOAA NHC HURDAT2 and NOAA SPC tornado and hail reports, through 2025 · Updated
1 tropical system has passed within 75 miles of Delavan, Wisconsin since 1851, 0 of them at hurricane strength; the most recent was an unnamed storm in 1900. Since 1950, 116 tornadoes have touched down within 25 miles, 5 of them rated EF3 or stronger.
- Hurricanes
- 0
- Tropical storms
- 1
- Tornadoes
- 116
- EF3 or stronger
- 5
within 75 mi, since 1851
below hurricane strength
within 25 mi, since 1950
26 deaths in all
What the records show for Delavan
None of the 1 tropical systems was at hurricane strength as it passed Delavan; the strongest was an unnamed storm in 1900, a tropical storm with 58 mph winds when its centre passed 3 miles away. Delavan is tied for the most tropical storms and hurricanes within 75 miles among the 416 Wisconsin cities on this site. The strongest of the 116 tornadoes within 25 miles was an F4 on April 21, 1967; its path came within 22 miles, and it killed 24 people. Of the 116, 11 had paths within 5 miles of the city centre, and 67 have come since 2000. June has had the most tornadoes, 25. The most recent tornado was on June 22, 2024. Delavan has more tornadoes within 25 miles than 84% of the 416 Wisconsin cities. Hail has been reported within 10 miles 56 times since 1967, with stones up to 2.5 inches (tennis ball size). Delavan has more hail reports within 10 miles than 52% of the 416 Wisconsin cities.
Compare Delavan's storm record with another city →
Tropical storms and hurricanes near Delavan
| Year | Storm | Closest | Strength when closest | Peak |
|---|---|---|---|---|
| 1900 | Unnamed 1900 stormSep 11 | 3 mi | Tropical storm (58 mph) | Category 4 |
Strength is the sustained wind on the track at the closest point, which is not the wind felt in Delavan: a hurricane's worst winds sit within a few dozen miles of its centre, and inland cities are usually past that.
Tornadoes within 25 miles of Delavan
By decade
- 2020s34
- 2010s18
- 2000s15(2 EF3+)
- 1990s10
- 1980s9
- 1970s11
- 1960s13(3 EF3+)
- 1950s6
| Date | Rating | Distance | Path | Killed / injured |
|---|---|---|---|---|
| Apr 21, 1967 | F4 | 22 mi | 25.5 mi | 24 / 450 |
| Jan 7, 2008 | EF3 | 17 mi | 10.78 mi | 0 / 15 |
| Jan 7, 2008 | EF3 | 12 mi | 13.1 mi | 0 / 5 |
| Jan 24, 1967 | F3 | 16 mi | 24.9 mi | 0 / 0 |
| Jul 19, 1963 | F3 | 14 mi | 10.6 mi | 0 / 0 |
| Oct 8, 1958 | F2 | 16 mi | 81 mi | 1 / 0 |
| Jun 22, 2024 | EF2 | 18 mi | 6.03 mi | 0 / 0 |
| Feb 8, 2024 | EF2 | 24 mi | 25.9 mi | 0 / 1 |
| Nov 22, 2010 | EF2 | 13 mi | 18.1 mi | 0 / 6 |
| Jun 21, 2010 | EF2 | 18 mi | 5.22 mi | 0 / 15 |
| Sep 28, 1986 | F2 | 17 mi | 9 mi | 0 / 1 |
| Jun 15, 1981 | F2 | 22 mi | 28.7 mi | 0 / 3 |
The strongest 12 of 116, by rating and then by deaths. Ratings before February 2007 are on the original Fujita scale.
Hail in Delavan
The Storm Prediction Center has 56 hail reports within 10 miles of Delavan since 1967, made on 36 separate days. Of these, 36 were 1 inch across or larger, and 3 reached 2 inches. The largest size, 2.5 inches (tennis ball size), was reported on 2 days, most recently May 2, 2018. The most recent report is from July 23, 2022. June has the most reports, 15.
Source: NOAA Storm Prediction Center severe weather reports, data through 2025.
Weather by month in Delavan
The nearest NOAA station with 1991–2020 climate normals is Lake Geneva Wwtp, WI, 11 miles east of Delavan at 846 feet. July is the warmest, with an average high of 86°F and low of 63°F; January is the coolest, at 30°F and 15°F. June is the wettest at 4.8 inches of precipitation on average and January and February the driest at 1.9 inches; the year adds up to 37.0 inches over 72 days with at least a tenth of an inch. Highs reach 90°F on about 21 days a year, almost all from June to September. Lows fall below freezing on about 136 nights a year. Snowfall averages 40.1 inches a year, most of it in January. That 37.0 inches is more than at 127 of the 165 Wisconsin stations used on this site (77%). Darien, 6 miles west, has its own station (Clinton Wwtp, WI): 37.8 inches a year, 0.8 more than here, and a July average high of 82°F against 86°F.
| Month | High °F | Low °F | Precip. in | Days ≥ 0.1" | Snow in |
|---|---|---|---|---|---|
| Jan | 30 | 15 | 1.9 | 6 | 13.9 |
| Feb | 35 | 17 | 1.9 | 4 | 8.1 |
| Mar | 45 | 26 | 2.3 | 5 | 4.8 |
| Apr | 59 | 37 | 3.5 | 8 | 2.6 |
| May | 72 | 48 | 4.1 | 9 | 0.0 |
| Jun | 81 | 58 | 4.8 | 8 | 0.0 |
| Jul | 86 | 63 | 3.7 | 6 | 0.0 |
| Aug | 83 | 61 | 3.3 | 6 | 0.0 |
| Sep | 76 | 54 | 3.7 | 6 | 0.0 |
| Oct | 63 | 42 | 3.0 | 6 | 0.2 |
| Nov | 47 | 31 | 2.5 | 6 | 3.4 |
| Dec | 35 | 21 | 2.3 | 4 | 7.1 |
| Year | 59 | 39 | 37.0 | 72 | 40.1 |
Averages for 1991–2020 at Lake Geneva Wwtp, WI (846 ft), from NOAA NCEI U.S. Climate Normals. Normals describe the station; the farther a place is from it, and the bigger the difference in height, the more its weather can differ.
Floods, thunderstorm wind and lightning near Delavan
Since 1996, the National Weather Service has logged 141 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Delavan: 131 thunderstorm wind reports, 5 flash floods, 3 heavy rain events and 2 floods. They killed 0 people and injured 13, and the NWS estimated $8.5 million in property and crop damage. The strongest thunderstorm gust on record here was 100 mph, on July 21, 1998. June has had the most flash floods, 3 of 5. Of the 374 Wisconsin cities on this site with a flash flood on record, 168 have had fewer than Delavan.
July 21, 1998: thunderstorm wind 5 miles from the centre of Delavan — 12 injured, $2.0 million damage.
June 10, 1999: thunderstorm wind in Delavan — 1 injured, $10,000 damage.
June 12, 2008: flash flood in Delavan — $4.8 million damage.
NWS: “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.”
Source: NOAA NCEI Storm Events Database, events whose starting point is on record, 1996 to June 30, 2026. Damage is the NWS estimate in the dollars of the year, not insured losses, and NWS notes that some reports are unverified.
Flood insurance claims, disaster declarations and FEMA risk ratings
Walworth County, which includes Delavan, has been named in 13 federal disaster or emergency declarations since 1965, 8 of them major disasters (by incident: 3 severe storms, 3 snowstorms, 2 biological emergencies, 2 floods). The latest major disaster declaration was Covid-19 Pandemic, on April 4, 2020. FEMA's National Risk Index gives Walworth County a Relatively Low rating for natural hazard risk overall; by hazard: Relatively High for hail; Relatively Moderate for tornadoes, inland flooding, strong wind and lightning; Relatively Low for heat waves; Very Low for hurricanes. It models the county's expected loss from all 18 hazards it covers at $39.7 million a year, the 18th highest of 72 Wisconsin counties; of the hazards above, the largest share, $17.6 million (44%), is from inland flooding.
Claims: FEMA, OpenFEMA Dataset FIMA NFIP Redacted Claims – v3, summed over ZIP codes; payments in the dollars of each year, not adjusted for inflation. Declarations: Disaster Declarations Summaries – v2, by county. Retrieved October 25, 2026. 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).
Risk ratings: FEMA, National Risk Index county table, December 2025 (v1.20), retrieved October 26, 2026; ratings compare counties nationwide, are meant for planning and are no substitute for a local risk assessment. This product uses the Federal Emergency Management Agency's National Risk Index dataset API or downloadable datasets 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).
What counts as a pass, the distances and the sources: how this storm history is built.