| June 2014 | Lightning | Downtown Janesville | 1 killed | A man was struck by lightning and killed when he got out of his vehicle on highway 14 to correct the windshield wiper. A line of severe thunderstorms was moving through the area at the time. |
| June 1998 | Lightning | Janesville | 5 hurt | no account filed |
| August 2000 | Thunderstorm Wind | Evansville | 2 hurt, $5,000,000 | no account filed |
| August 1998 | Flash Flood | Clinton | 2 hurt, $250,000 | no account filed |
| June 1999 | Thunderstorm Wind | Evansville | 2 hurt, $3,000 | no account filed |
| July 1991 | Thunderstorm Wind | not stated | 2 hurt | no account filed |
| February 2024 | Tornado (EF2) | Magnolia | 1 hurt, $6,800,000 | Beginning section of the second tornado to ever occur in February in Wisconsin. Storm chaser/spotter/public videos show the tornado beginning around 5:39pm south of Evansville. The tornado intensified as it tracked to the east of Evansville where it impacted 30 primary residences (2 destroyed, 10 major impacts, 13 minor impacts, 5 affected). Numerous barns and outbuildings were destroyed along the path as it tracked to the northwest of Edgerton. The main EF-2 damage was confined to a stretch from east of Evansville to just southwest of the Yahara River. There was one person in a car that was hit by the tornado that had injuries serious enough to warrant transportation to the hospital, but they were deemed minor and released. Almost every person that was impacted by the tornado that the damage surveyors talked to said that they received the warning via Wireless Emergency Alert on their cell phone and then went to their shelter to gather more information via TV, radio, social media. County wide estimates of damage was at about $2.5 million. |
| August 1998 | Flash Flood | Janesville | 1 hurt, $1,500,000 | no account filed |
| November 1971 | Tornado (F2) | not stated | 1 hurt, $250,000 | no account filed |
| October 1970 | Tornado (F2) | not stated | 1 hurt, $250,000 | no account filed |
| September 1997 | Strong Wind | Janesville | 1 hurt, $1,000 | no account filed |
| July 2009 | Lightning | Clinton | 1 hurt | A 44-year-old woman was struck by lightning while standing in the doorway of a barn holding the reins of a horse. She was taken to Beloit Memorial Hospital and treated in the emergency department. |
| August 1989 | Thunderstorm Wind | not stated | 1 hurt | no account filed |
| May 1988 | Thunderstorm Wind | not stated | 1 hurt | no account filed |
| April 2026 | Flash Flood | Downtown Janesville | $30,000,000 | Around 700 911 calls mainly attributed to flash flooding. Flash flooding of streets and yards in Janesville with basement flooding in many homes. Many vehicles stranded in deep water. A bridge was washed out due to the flooding of Fisher Creek over Rockport Rd. Severe flooding of a church, and the basement of an elementary school. The school's mechanical systems and main power panel were destroyed. The school has been closed. RAJ stadium flooded. A train derailment in downtown Janesville with 3 locomotives off the tracks, due to a sinkhole. 1st responders conducted a water rescue of the engineer using a rope. |
| June 2024 | Tornado (EF2) | Afton | $24,800,000 | The tornado began just west of Murray Rd, north of Bass Creek where portions of several trees were snapped. The tornado quickly grew, moved to the east-northeast and produced damage rated EF-1 neighborhoods near Loch Lomond park. EF-2 damage was noted at a residence on the east side of county highway D where well over one hundred trees were snapped or uprooted. The tornado continued to the northeast, crossing the Rock River, Highway 11 and Highway 51 producing damage rated EF-1. The second area of EF-2 damage was noted a neighborhood just northwest of Burbank Park, where a house lost its roof and a portion of its second story. The roof was found to the north-northwest over a block away. The tornado continued northeast crossing Beloit Ave. and ending in the fields to the west of South Read Rd. Damage along the majority of the path was rated EF-1. Tree damage was substantial with well over 1000 trees that were snapped, uprooted or had large sections damaged. Roof damage on several structures included shingle loss, occasional loss of roof decking material, peeled or dislodged siding and other facia and soffit peeling and removal. A few structure sustained damage to walls when their garage doors were breached. Numerous power poles were leaning, with several snapped. |
| April 2006 | Hail | Union | $4,360,000 | no account filed |
| August 1998 | Lightning | Beloit | $3,500,000 | no account filed |
| March 1991 | Tornado (F2) | not stated | $2,500,000 | no account filed |
| April 1965 | Tornado (F1) | not stated | $2,500,000 | no account filed |
| June 1998 | Tornado (F2) | Leyden | $845,000 | no account filed |
| April 1996 | Thunderstorm Wind | Beloit | $800,000 | no account filed |
| March 2023 | Tornado (EF0) | Beloit | $600,000 | Tornado started in the center of Beloit in the Merrill Park area. The tornado uprooted numerous trees along its path through the eastern side of the city toward the Turtle area. The path then went east and appears to have crossed I-39 before ending in a field. |
| August 1998 | Flash Flood | Janesville | $550,000 | no account filed |
| August 2007 | Flash Flood | Evansville | $500,000 | Several rounds of thunderstorms with heavy rains on top of a saturated ground resulted in scattered flash flooding from the Evansville area to the Janesville vicinity. Water damage to basement contents and/or basement walls, as well as fast-flowing water depths of 6 inches to 1 foot on roads, were reported in the Civil Towns of Avon, Fulton, Magnolia, Union, and Plymouth. Some soil erosion, gravel washouts, and crop damage were noted. Badfish Crreek and Allen Creek just east and northeast of Evansville exceeded flood stages by 3 to 5 feet and overflowed adjacent roads.||August, 2007, rainfall totals include: 17.39 at Afton, 13.15 in Beloit, 16.24 in Clinton, 15.22 in Milton, and over 17 in Janesville. |
| August 1993 | Thunderstorm Wind | Evansville | $500,000 | no account filed |
| June 2008 | Flash Flood | Orfordville | $462,160 | Heavy rains resulted in flash flooding across much of the northwest half of the county. Water depths on road surfaces reached 3 feet or more and there were gravel washouts. Two hundred thirty-nine homes had minor damage, 9 homes had major damage, and 26 were destroyed (total of $7.46 million for all home property losses). Fifty-four businesses had minor damage, and 24 had major damage (total business losses were about $810 thousand. Crops losses were estimated at $15 million). Public sector damage was about $10.3 million. There were several roads and bridges that sustained damage. |
| April 2026 | Tornado (EF1) | Tiffany | $408,000 | Brief tornado that caused damage near Maple Lane southeast of Janesville. Storm chaser video confirmed a brief tornado in this area. More widespread damage occurred west and east of this track due to downburst winds. |
| April 1995 | Thunderstorm Wind | Beloit | $350,000 | no account filed |
| July 2005 | Tornado (F1) | Milton | $300,000 | A tornado spun up at 1507CST about 4 miles north-northeast of Milton (Rock Co.). about 1/4 mile north of the intersection of Vickerman Rd. and Godfrey Rd. It traveled east-southeast for 2 miles and dissipated just northwest of the intersection of McCord Rd. and Salisbury Drive. On Godfrey Rd it destroyed one large barn, severely damaged another barn, destroyed a shed, and inflicted minor damage to a home. Otherwise many large trees were uprooted or shredded, and a couple power lines were ripped. |
| April 2001 | Thunderstorm Wind | Evansville | $300,000 | no account filed |
| June 2000 | Flash Flood | Countywide | $300,000 | no account filed |
| July 1999 | Thunderstorm Wind | Orfordville | $300,000 | no account filed |
| July 2007 | Lightning | Downtown Janesville | $275,000 | A 2-story Janesville home was destroyed by a fire after ligntning struck it. |
| May 1991 | Tornado (F1) | not stated | $250,000 | no account filed |
| May 1988 | Tornado (F2) | not stated | $250,000 | no account filed |
| April 1978 | Tornado | not stated | $250,000 | no account filed |
| June 1969 | Tornado (F1) | not stated | $250,000 | no account filed |
| April 2026 | Tornado (EF1) | Emerald Grove | $215,000 | Brief tornado went through Emerald Grove, destroying a barn and causing damage to an antique store. Significant tree damage along the path as well with debris lofted well to the ENE from the structures. |
| March 2023 | Tornado (EF0) | Magnolia | $200,000 | Tornado started just south of Decatur Lake and tracked to the north through Decatur Lake Golf Course, causing some minor tree damage. Further to the north, a barn had roof damage with a number of sheets of metal lofted off of the building. Tornado tracked into a small portion of Rock County before dissapating. |
| July 2005 | Thunderstorm Wind | Milton | $200,000 | no account filed |
| May 1999 | Thunderstorm Wind | Janesville | $175,000 | no account filed |
| August 2009 | Thunderstorm Wind | Milton | $150,000 | Police reported numerous trees and power lines down between Milton and Janesville. Roof damage was reported in Janesville from the thunderstorm wind gusts, and several homes were damaged by tree debris. One home had some windows blown out. Barn damage was noted in the countryside around Janesville. A 68 knot (78 mph) wind gust was recorded at the Janesville Airport (KJVL). |
| August 2007 | Heavy Rain | Evansville | $150,000 | Urban and small stream flooding occurred across the northern third of Rock County after 3 to 4 inches of rain fell overnight. Water depths on roads reached a foot, especially in the Evansville and Edgerton areas, however no roads were closed. Reports indicated that the flood waters were not fast flowing, nor did they pose a danger to the public. Some crop damage was noted. Overnight rainfall of 6.4 inches were measured by a spotter in Edgerton. Local residents near Badfish Creek, west of Cooksville, noted that this creek flooded and merged with Frog Pond Creek and the water was 3.5 feet deep between the creeks. |
| June 1996 | Flash Flood | Cooksville | $150,000 | no account filed |
| July 2011 | Thunderstorm Wind | Orfordville | $125,000 | Law enforcement officials in Rock County reported trees and power lines down in a 23-mile wide swath from west northwest of Orfordville to northeast of Clinton due to damaging thunderstorm wind gusts estimated at 65 knots (75 mph). Corn crops, valued at $700,000, were also flattened. A home in downtown Janesville had a bedroom addition crushed when a tree fell on it. The winds also blew down a barn on Creek Road where it crosses Turtle Creek, as well as a giant 22-foot, 2,000 pound fiberglass pumpkin off of a 65-foot tall silo at Meyer's Farm Market north of Janesville. |
| April 2026 | Tornado (EF1) | Johnstown Center | $124,000 | Multivortex tornado documented southwest of Richmond. Multiple sheds with sheet metal damage along County Highway M before entering Walworth County. |
| May 2024 | Tornado (EF0) | Leyden | $112,000 | Tornado mainly caused tree damage as it tracked from west of Janesville and ended northeast of Milton after going through the northern side of the city. Some areas west of Janesville had extensive, yet narrow tree damage. In Milton, it was mainly large trees that were knocked over though the DPW garage had two doors blown in. Storm chasers and spotters documented this tornado and shared their videos and pictures with NWS. |
| July 2022 | Lightning | Beloit | $100,000 | A lightning strike and subsequent fire to a residential home resulted in significant damage. |
| July 2015 | Tornado (EF1) | Johnstown | $100,000 | Three old barns were mostly destroyed. Fields of corn partially blown over. Large trees snapped. |
| June 2010 | Thunderstorm Wind | Downtown Janesville | $100,000 | Powerful thunderstorm winds raked the city of Janesville. At least 50 large trees were uprooted, and numerous power-lines were down. A metal roof of a business was ripped off by the winds. Elsewhere, a tree fell on a flatbed truck (minor damage), and a carriage house roof was blown off. Heavy rains resulted in minor urban flooding and a couple stalled vehicles. |
| July 2005 | Thunderstorm Wind | Milton | $100,000 | no account filed |
| August 2004 | Thunderstorm Wind | Afton | $100,000 | no account filed |
| July 1998 | Thunderstorm Wind | Janesville | $100,000 | no account filed |
| May 2012 | Lightning | Edgerton | $75,000 | Fire officials say lightning ignited a fire that damaged a 21-unit senior living facility in Edgerton, displacing 30 residents. |
| June 2008 | Thunderstorm Wind | Evansville | $75,000 | Powerful thunderstorm winds knocked down large trees and power-lines. |
| July 2006 | Thunderstorm Wind | Union | $75,000 | Trees and power lines down in a large swath from northwestern to southeastern Rock County. In the city of Janesville, at least 3 cars were damaged by felled trees or tree branch debris. Several roads were temporarily blocked by tree debris. |
| May 1999 | Thunderstorm Wind | Emerald Grove | $75,000 | no account filed |
| October 1996 | Lightning | Johnstown | $75,000 | no account filed |
| April 1997 | Thunderstorm Wind | Beloit | $65,000 | no account filed |