| September 1951 | Tornado (F4) | not stated | 1 killed, 9 hurt, $250,000 | no account filed |
| August 1963 | Tornado (F3) | not stated | 13 hurt, $250,000 | no account filed |
| August 1963 | Tornado (F3) | not stated | 13 hurt, $250,000 | no account filed |
| August 1963 | Tornado (F3) | not stated | 13 hurt, $250,000 | no account filed |
| June 2008 | Tornado (EF2) | Pardeeville | 6 hurt, $2,500,000 | This tornado was extremely wide since the thunderstorm cloud base was very low and the meso-cyclone that is usually aloft was well-formed all the way to the ground. Within a broad 1 to 2 mile wide area of EF0 to EF1 damage, there were several small swaths of EF2 damage due to multiple votices. The accompanying graphic shows this effect. With respect to residential homes this tornado resulted in very minor damage to 150, minor damage to 30, major damage to 10, and 2 were destroyed (total residential damage of $2 million). With respect to agricultural buildings ($500K in total damage), this tornado resulted in minor damage to 20, and major damage to 2 buildings (inlcuding silos). Tens of thousands of trees were uprooted or chewed-up, and many power-lines and power-poles were either toppled or damaged. About 4000 to 6000 trees on a tree farm were destroyed at a location about 3 miles east-southeast of Pardeeville. This tree-farm loss was treated as a crop loss. Additionally, some corn and soybean crops were damaged. This tornado started just southeast of the intersection of CTH P and Pardeeville Road, and moved southeastward for about 4 miles and then traveled east-southeast to end just northeast of the western intersection of STH 146 and CTH A. The specific starting point and ending point lat/long numbers were 43.53333/-89.26306 and 43.49556/-89.09878, respectively. Additional mid-point pairs of number include: 43.51603/-8922394, 43.50728/-89.20151, and 43.50208/-89.17679. DI#24 (ELT), DOD4. The wind speeds were estimated at about 120 mph. Average path length was about 1760 yards (1 mile). |
| May 1998 | Thunderstorm Wind | Countywide | 1 hurt, $3,640,000 | no account filed |
| June 1984 | Tornado (F3) | not stated | 1 hurt, $2,500,000 | no account filed |
| June 2008 | Thunderstorm Wind | Rio | 1 hurt, $25,000 | Powerful thunderstorm winds knocked down large trees and power-lines. One injury reported at Rio campground when tree branches hit a person. |
| June 1996 | Lightning | Wyocena | 1 hurt, $2,000 | no account filed |
| May 1989 | Thunderstorm Wind | not stated | 1 hurt | no account filed |
| June 2006 | Hail | Dekorra | $500,000,000 | A slow-moving thunderstorm moved from the Dekorra area southeast through the Poynette area to the North Leeds area, leaving in its wake a lot of crop damage due to hail. A roughly 40 to 45-minute hail shower (stones up to the size of quarters) fell in a band from about 3 miles south-southeast of Dekorra along Kent Rd. to the McKenzie Environmental Education Center just northeast of Poynette. Crop, vegetable, and fruit damage was noted, and in some cases, an entire year's crop was lost due to hail damage. Many residential homes and vehicles were damaged. Hail depth on some roads reached 8 inches and had to be plowed off the roads, especially along Kent Rd. and near the McKenzie Center. The crop damage estimate is based on a newspaper report which quoted a USDA report. The property damage is purely an estimate based on a variety of reports. |
| June 2008 | Flash Flood | Okee | $15,660,000 | Heavy rains resulted in a flash flood event that washed out some raods and gravel shoulders in the western part of the county. This event was one of 3 flash flood events over parts of Columbia County on 3 separate days. Two started on June 7th, and one on June 8th. In all 3 flash flood events, home and business damage was reported, and there was crop damage. Some farm fields remained flooded into early July. It was nearly impossible to break down the damages by flash flood. Therefore, the collective damage breakdown for these events is provided in this June 8th flash flood StormData entry for Columbia County.||The breakdown for residential home losses were: over 1500 minimally affected, 45 with minor damage, 26 with major damage, and 5 destroyed (total of $10 million for home losses). Total business losses were about $2 million. Crop losses were estimated at about $40 million. Public sector damage was about $3.66 million. There were several roads and bridges that sustained damage. |
| August 2004 | Hail | Rio | $6,000,000 | no account filed |
| August 2004 | Thunderstorm Wind | Rio | $3,000,000 | no account filed |
| June 1984 | Tornado (F2) | not stated | $2,500,000 | no account filed |
| September 2010 | Flood | Wisconsin Dells | $1,230,000 | The river at the gage in Portage was in flood from the evening of September 24th through the morning of September 30th, and reached a record flood level of 20.66 feet during the evening of Monday, September 27th. The old record crest at Portage was 20.50 feet on 09/14/1938. The flood waters threatened to break through a century-old earthen dike in the Civil Township of Caledonia. The waters seeped through the dike, but the dike did not fail. The potential levee failures caused voluntary evacuations and road closures along the river from the Dells to Portage. As it turned out, dozens of homes in the Blackhawk Park area just southeast of Portage were cut off when water depths reached a foot on the only road into the area. The Columbia County Emergency Management Director provided the following loss estimates: $1 M for seasonal and full-time residental homes, $100,000 for patching and reinforcing part of a 14-mile earthen berm/dike, $50,000 for gravel shoulder washouts, $75,000 to a wastwater treatment plant, and $200,000 to bottomland crops. It was postulated that damage was limited due to the fact that the flood waters rose slowly which reduced the erosional power of water. The EM Director also noted that the Wisconsin River levels in Portage were about a foot higher than that experienced in the Great Flood of 1993, while at Wisconsin Dells the 2010 level was about a foot lower than that experienced in 1993. |
| July 2015 | Thunderstorm Wind | Columbus | $1,000,000 | Widespread tree damage in the city of Columbus with many of the roads blocked by debris. A State of Emergency was declared in the city. Numerous large tree branches and trunks snapped. Some large trees uprooted. A few trees downed on homes. Some power poles knocked down or leaning. The Red Cross opened a shelter at Columbus Middle School for those without power in order to seek relief from the heat and humidity. |
| June 2004 | Flash Flood | Cambria | $1,000,000 | no account filed |
| August 2007 | Flash Flood | Okee | $750,000 | Significant flash flooding affected the southwest half of Columbia County, especially from the Okee area near Lake Wisconsin/Wisconsin River over to the Lodi area. Several landslides were noted in the Civil Town of West Point area along the Wisconsin River. A pavement washout closed STH 188 in the Civil Town of West Point. Water depths on STH 188 reached 2 to 4 feet. A small pier on Lake Wisconsin was washed out by the fast flowing drainage water coming in fromt the countryside. A private road about 2.5 miles northeast of Harmony Grove had a washout. Gravel shoulder washouts occurred on several other roads ($50,000 damage) and crops across the southwest part of the county were damaged. Fifty-five residential homes sustained minor damage to basement contents, and 2 homes were destroyed by the flood waters. Three businesses sustained minor flood damage.||August, 2007, rainfall totals include: 11.33 at the Arlington Farm, 15.18 in Lodi, and 14.70 7WNW Poynette (near the Wisconsin River). |
| April 2008 | Tornado (EF1) | Dekorra | $600,000 | A long-tracked, partially rain-wrapped, tornado traveled through mostly rural areas of Columbia County and affected only a small portion of one village; otherwise property damage would have been more extensive. This tornado spun up about 2.75 miles east of Dekorra, just northwest of the intersection of STH 51 and CTH VJ, near Columbia Lake. It then tracked east-northeast through the far southeast reaches of the village of Wyocena, and crossed STH 22 just north of Patchin Road. It then moved through the intersection of CTH G and W. Hill Road, where the last structural damage to a couple barns and home occurred. Thereafter, this tornado tracked more northeast through rural areas (crossing STH 33 midway between Cunningham Road and Englehart Road), and eventually exited Columbia County just east of North County Line Road and Sterk Road. It continued for a few more miles through southeastern Green Lake County. Based on ground damage evidence, this tornado briefly lifted a couple times when it was north of STH 33. Most of the structural damage occurred south and southeast of Wyocena. Otherwise the rural damage consisted of uprooted trees or broken branches. At least two trained spotters video taped the tornado.||The Columbia County Emergency Management situation report indicated that 4 residential homes sustained minor damage, and 1 home suffered major damage. Additionally, 2 farm buildings had minor damage, 2 suffered major damage, and 3 were destroyed. The report estimated that private sector damage totaled about $550,000 (excluding electrical line damage). Public sector debris clearance totaled $3500, and protective measures totaled $1000. The Sheriff's Office had to close down 4 roads until power lines and trees could be cleared. Electrical line replacement is estimated at about $50,000. The lat-long pairs of numbers for this tornado segment in Columbia County include: N43.46179/W89.41637, N43.49223/W89.27809, N43.54813/W89.18491, and N43.63221/W89.06693. On the EF-scale, DI #1 (SBO) was used with a DOD of 6, for an EF-rating of EF1 and an wind estimate of about 100 mph (87 knots). |
| June 2006 | Tornado (F1) | Portage | $600,000 | This tornado segment is a third, county-segment, continuation of a tornado that initially spun up in far northwestern Columbia County about 3.0 miles east of Wisconsin Dells at 1754CST and then crossed into Sauk County about 1.5 miles southeast of Lewiston at 1813CST. This tornado re-entered Columbia County about 7.0 miles west of Portage at 1817CST where Levee Rd. on the south side of the Wisconsin River exits Columbia County going west. The heading of this tornado was southeast, and it crossed Interstate 90/94 near Tritz Road where a vehicle swerved and caused a semitrailer to roll onto its side. It eventually passed through a residential trailer complex/camp ground south of the Cascade Ski Resort. It crossed Interstate 90/94 where Ziehmke Rd approached the Interstate from the east. At this point, the tornado caused a semitrailer to be blown off the road. The tornado then tracked over the extreme eastern edge of Pickerel Lake, crossed over the Wisconsin River for the second time, and dissipated about 1.0 mile southwest of Dekorra at 1840CST, just short of CTH V. Around 10 houses were damaged, along with a barn, a couple pole sheds, and many trees and power lines. The tornado caused about 600,000 dollars in property damage, and was rated F1 with winds of 64-97 knots (73-112 mph). The tornado was well-photographed and filmed. Overall, this F1 Columbia-Sauk-Columbia County tornado path length was 16.9 miles with a beginning time of 1754CST and an ending time of 1840CST. |
| July 2021 | Tornado (EF1) | Dekorra | $500,000 | This was 1 of 17 tornadoes to occur in Wisconsin on the night of July 28th into the early morning hours of July 29th. This was the 5th overall tornado for the event.|A line of storms developed in northern Wisconsin and pushed south into southern Wisconsin in the overnight hours of the 28th into the 29th of July with mainly brief tornadoes and damaging winds occurring.||This tornado began in the Baraboo River Waterfowl Production Area just north of the I-94/I-39 split south of Portage. The tornado crossed the interstate and hit the I-39 Supply facility where 84 trailers were damaged or destroyed. The tornado continued to the southeast where it caused extensive tree damage through mainly rural areas. The last area of noted damage was to a large metal farming shed north of Thunderbird Drive. |
| June 2006 | Tornado (F1) | Wisconsin Dells | $400,000 | The first segment of a multi-county-segmented tornado spun up 3.0 miles east of Wisconsin Dells at 1754CST about 0.6 mile east-northeast of the intersection of Broadway Rd. and CTH Q. It headed southeast and crossed STH 16 at Lewiston, and then crossed the Wisconsin River into Sauk County about 1.5 miles southeast of Lewiston at 1813CST. In this first Columbia County stretch, around 10 houses were damaged or destroyed, along with a couple pole sheds and many trees and power lines. An estimated 400,000 dollars in property damage occurred. The tornado was rated F1 with winds of 64 to 97 knots (73-112 mph). After a short track through Sauk County, this tornado re-entered Columbia County about 7 miles west of Portage, crossed Interstate 90/94, and then crossed the Wisconsin River again before dissipating at 1840CST. |
| August 2004 | Thunderstorm Wind | Pardeeville | $400,000 | no account filed |
| May 1988 | Tornado (F1) | not stated | $250,000 | no account filed |
| June 1984 | Tornado (F5) | not stated | $250,000 | no account filed |
| June 1984 | Tornado (F2) | not stated | $250,000 | no account filed |
| June 1984 | Tornado (F1) | not stated | $250,000 | no account filed |
| April 1976 | Tornado (F1) | not stated | $250,000 | no account filed |
| August 1966 | Tornado (F2) | not stated | $250,000 | no account filed |
| June 2013 | Thunderstorm Wind | Portage | $150,000 | The Columbia County 911 Call Center reported approximately 100 trees were blown down, many power lines downed and scattered clusters of damage along a 17 mile-wide path from 5 miles southwest of Portage to Columbus from damaging thunderstorm wind gusts that were estimated up to 80 mph. A trained spotter recrded a 71 mph wind gust in Pardeeville. The roof was blown off a home and a garage was destroyed in Fall River. A home was destroyed and 2 houses damaged in the Town of Dakorra. Heavy rain accompanying the storms, with 1.58 inches measured in 45 minutes 3 miles east of Poynette, produced street flooding in Portage and Pardeeville. |
| June 1996 | Flash Flood | Portage | $150,000 | no account filed |
| August 2010 | Flash Flood | Okee | $125,000 | Several rounds of thunderstorms produced heavy rain that closed numerous roads in Caledonia Township, west of the Wisconsin River and southwest of the city of Portage. The rushing water damaged roadways and washed out gravel shoulders, as well as causing damage to private driveways. |
| August 2020 | Flash Flood | Wisconsin Dells | $100,000 | Many roads impassible in Portage from flash flooding. Many vehicles stranded or flowing within the deep floodwaters with several water rescues executed. Also, yards and basements flooded in Portage. Elsewhere in northern Columbia County, road and culvert washouts on highway P east of Pardeeville, and in the townships of Fort Winnebago and Lewiston. Rising waters on Swan Lake flooded out some homes on the northwest side of the lake. Portions of the Fox River flooded from northeast Columbia County to Pardeeville. The Fox River floodwaters flooded a portion of highway 44 northeast of Marcellon. The Pardeeville DPW sandbagged the sanitary sewer manholes to reduce the constant running of the lift stations. |
| July 2010 | Tornado (EF1) | Cambria | $100,000 | An EF1 tornado developed about 2.5 miles southwest of Cambria, about 0.25 miles northeast of the intersection of Old B Road and Welsh Prairie Road, and moved east-northeast to around 2.1 miles east-southeast of Cambria, ending near Fordeg Road just north of Cemetery Road. The tornado moved across a farm where it collapsed the walls of a barn, ripped the fabric off of a shed, moved a fertilizer spreader 300 to 400 feet and pushed a shed door 6 inches. Additionally, 15 acres of corn and 5 acres of wheat were flattened, and numerous trees were uprooted or had branches snapped off. The average path width was 40 yards. The EF1 estimated wind speed of 90 to 95 mph was based on DI 1(SBO) DOD6. The exact start location is Lat 43.52061 Lon -89.14369. The exact end location is Lat 43.53732 Lon -89.06274. |
| July 2010 | Flash Flood | Portage Arpt | $100,000 | Law enforcement officials reported numerous road closures and culverts damaged due to deep and rushing water over roads from near Portage to Randolph, and south to the Dane County border. Included in these reports was damage to culvert supports in the Harmony Grove subdivision and damage to roads shoulders and driveways along Cactus Acres Road in Lodi; knee-high water covering Henry Drive in Portage. Storm total rainfall reports include 3.68 inches in Lodi; 3.58 inches in Arlington; and 2.58 inches near the Wisconsin Dells, with much of the rain falling within one to two hours of time. |
| June 2002 | Lightning | Pardeeville | $100,000 | no account filed |
| May 2001 | Lightning | Rio | $100,000 | no account filed |
| August 1996 | Thunderstorm Wind | Columbus | $100,000 | no account filed |
| June 2000 | Flash Flood | Countywide | $96,800 | no account filed |
| July 1997 | Lightning | Portage | $80,000 | Much of a barn and most of it's contents were destroyed in a lightning induced fire. |
| June 2020 | Thunderstorm Wind | Portage | $75,000 | Numerous trees and branches down from the Portage area toward Pardeeville, some landing on homes, sheds, and vehicles. Some shingle and shutter damage to homes. Damage to street signs, billboards and other large signs. A large 5th wheel camper tipped over near the Swan Lake State Wildlife area. |
| August 2007 | Lightning | Portage | $75,000 | Lightning started a fire that substantially damaged a 2-story home. |
| June 2022 | Thunderstorm Wind | Pardeeville | $70,000 | Numerous large trees and branches snapped on the golf course and surrounding neighborhood adjacent to Swan Lake. A large porch roof and overhang of a large and new lake home was ripped off and deposited on the other side of the house. |
| July 2010 | Flash Flood | Lodi | $60,000 | The Columbia County Emergency Manager reported gravel shoulder wash-outs on several roads and one to two feet of water on low-lying roads from heavy rains as strong to severe thunderstorms crossed the region. Minor crop damage was also noted. |
| June 2018 | Flash Flood | Dekorra | $51,260 | Approximately 9 roads in the Town of Caledonia were closed due to flooding and washouts. Road repairs were needed. |
| April 2026 | Thunderstorm Wind | Portage | $50,000 | Multiple barns with roof damage, and scattered trees and powerlines down throughout the county. |
| March 2019 | Flood | Okee | $50,000 | Ice jams on Spring Creek and the Crawfish River led to significant flooding in the Lodi and Columbus areas, respectively. Several businesses in the downtown area of Lodi were flooded, and roads were flooded and closed upstream and downstream of Spring Creek. An ice jam at the highway 16/60 bridge in Columbus caused significant flooding near the river. 40 residents were evacuated from apartments and homes. Highway 16/60 was closed from County Road TT in Dodge County to highway 73 in Columbus. Additional road closures occurred upstream on the branches of the Crawfish River near the Village of Fall River and Doylestown. Just southwest of Columbus, County Highway K was closed due to flooding from Robbins Creek. Farther north, the Fox River flooded, including Park Lake in Pardeeville, where severe erosion occurred to one property losing trees and soil along its shoreline. Highway 44 was closed in a couple sections northeast of Pardeeville due to the flooding of the Fox River. In the southwest portion of the county, the Crystal Lake Campground and RV Park was evacuated due to the high levels of Crystal Lake on March 15th, but conditions improved by the next day.|Flooding also occurred in low lying areas across the county which closed a few additional rural roads, including south of Arlington and a small section of highway 188 in the Town of West Point near Lake Wisconsin. |
| April 2008 | Lightning | Portage | $50,000 | Lightning struck the steeple of Bethlehem Lutheran Church in Portage, resulting in a fire. The event time is estimated, and the actual time could have been up to an hour or two earlier since other storms visited the area prior to 1630 CST. |
| August 2007 | Thunderstorm Wind | Portage | $50,000 | Powerful thunderstorm wind gusts to 56 knots (65 mph) toppled many trees and damaged several power-lines. |
| August 2007 | Thunderstorm Wind | Cambria | $50,000 | Powerful thunderstorm wind gusts to 56 knots (65 mph) toppled many trees and damaged several power-lines. |
| August 2007 | Thunderstorm Wind | Rio | $50,000 | Powerful thunderstorm wind gusts to 56 knots (65 mph) toppled many trees and damaged several power-lines. |
| August 2007 | Lightning | Portage | $50,000 | Lightning started a fire that substantially damaged a 2-story home. |
| May 2000 | Flash Flood | South Portion | $50,000 | no account filed |
| June 2006 | Flash Flood | Wyocena | $40,000 | Thunderstorms with torrential rainfall of 3 to 6 inches (radar estimated) within a couple hours caused low spots on several roads to be washed out near Poynette. In addition, there were other washouts of gravel shoulders on some roads. Several roads had water depths of 1 to 2 feet on low spots. |
| April 2026 | Thunderstorm Wind | Lodi | $35,000 | Dozens of trees snapped, uprooted, or downed in Lodi. Powerlines down as well. A small portion of a roof collapsed at a nursing home. |
| July 2016 | Thunderstorm Wind | Friesland | $35,000 | The roof and walls of barn collapsed. Some damage to the roof and walls of a home. |
| July 1997 | Thunderstorm Wind | Pardeeville | $35,000 | no account filed |
| April 2026 | Thunderstorm Wind | Columbus | $30,000 | Two large trees blown down and a pine tree snapped at 80 feet high in a neighborhood. Additional trees and tree limbs down in the neighborhood and across Columbus. One tree felled on a home causing roof damage. |
| April 2019 | Flood | Lewiston | $30,000 | The WI River at Portage reached major flood stage, cresting at 20.08 feet the late evening of April 21st. Much of the Blackhawk Park and Long Lake areas and its numerous roads and some homes are flooded. Some evacuations occurred in these areas. In the city of Portage, portions of W. Conant St. and Summit St. are flooded including the boat launch. Water rises through the ground and floods portions of Sunset and Franklin Streets. The Fire Department built a berm on Summit St. which prevented the expansion of flooding into more residential areas. Basement flooding was occurring |for homes near the floodwaters. Upstream from Portage, Levee Rd. is closed from highway 33 just south of Portage to Schepp Rd. in Sauk Co. Residents living on Levee Rd. were evacuated due to some erosion of the Caledonia levee which protects the area from substantial flooding. Portions of River Shores Rd. was also flooded on the east side of the river. Downstream from Portage in the Town of Dekorra, around a dozen homes are flooded on highway V. Portions of highway V, River Oaks Rd., and Oak Knoll Dr. are flooded. Across the river and slightly upstream from the Town of Dekorra, a portion of Thunderbird Rd. is flooded. |