| 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. |
| 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 |
| 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. |
| April 2026 | Thunderstorm Wind | Portage | $50,000 | Multiple barns with roof damage, and scattered trees and powerlines down throughout the county. |
| 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 | Lightning | Portage | $50,000 | Lightning started a fire that substantially damaged a 2-story home. |
| June 2000 | Thunderstorm Wind | Portage | $30,000 | no account filed |
| June 2017 | Thunderstorm Wind | Portage | $25,000 | Many large trees down. Roofs were torn off small sheds. |
| June 2008 | Thunderstorm Wind | Portage | $25,000 | Powerful thunderstorm winds knocked down large trees and power-lines. |
| August 2018 | Flash Flood | Portage | $15,000 | Flash flooding of streets in Portage with some cars stranded in flood waters. |
| September 2012 | Thunderstorm Wind | Portage | $15,000 | Law enforcement officials reported trees were blown down by damaging thunderstorm wind gusts estimated at 56 knots (65 mph) in an 5-mile wide swath from Portage to Pardeeville. |
| May 2004 | Lightning | Portage | $15,000 | no account filed |
| July 2021 | Thunderstorm Wind | Portage | $12,000 | Numerous reports of downed trees and limbs. |
| June 2019 | Thunderstorm Wind | Portage | $12,000 | Widespread branches and trees down including some large in Portage. |
| June 2024 | Flood | Portage | $10,000 | Water surrounds seasonal homes along Old River Rd. in the Blackhawk Park area including water at the base of Caledonia/Lewiston Levee on Old River Rd. Old River Rd., W Lake Rd., Sec K Rd., and Blackhawk Rd. are all covered with water. West Lane Rd. in the Long Lake area has 4 feet of water over it in places. Farther south in the Town of Dekorra, about 12 homes are flooded on Hwy V. Water also over River Oaks Rd. and Oak Knoll Rd. near Hwy V. |
| March 2019 | Flood | Portage | $10,000 | The WI River at Portage reached minor flood stage, cresting at 17.73 feet the early morning of March 28th. In the Blackhawk Park area in the Town of Caledonia, Old River Road is closed with water over it. West Lane Road in the Long Lake area is closed with about 4 feet of water over it in places. Wood Street is affected by floodwaters. In the Town of Dekorra, floodwaters are over portions of Oak Knoll Road and River Oaks Road. Several homes have water in the first floor and there is also flooding of outbuildings and yards. |
| July 2008 | Thunderstorm Wind | Portage | $10,000 | Powerful thunderstorm wind gusts toppled several large trees and broke branches that brought down some power-lines. |
| July 2006 | Thunderstorm Wind | Portage | $10,000 | Trees toppled and some power-lines downed. |
| July 2005 | Thunderstorm Wind | Portage | $10,000 | no account filed |
| June 1996 | Thunderstorm Wind | Portage | $10,000 | no account filed |
| June 1996 | Thunderstorm Wind | Portage | $9,000 | no account filed |
| May 1998 | Thunderstorm Wind | Portage | $7,000 | no account filed |
| March 2020 | Flood | Portage | $5,000 | The WI River at Portage reached moderate flood stage due to melting snow and rainfall. It crested the early morning of April 1st at 18.18 feet. Numerous roads are flooded in the Blackhawk Park and Long Lake areas across the river from Portage. Floodwaters surround seasonal homes along Old River Rd. Water is at the base of the Caledonia/Lewiston Levee near Old River Rd. In the Town of Dekorra, water is over portions of River Oaks Rd. and Oak Knoll Dr., while about a dozen homes are flooded on Hwy V. This flooding continued into early April. |
| April 2020 | Flood | Portage | $5,000 | The WI River at Portage reached moderate flood stage due to melting snow and rainfall. It crested the early morning of April 1st at 18.18 feet. Numerous roads are flooded in the Blackhawk Park and Long Lake areas across the river from Portage. Floodwaters surround seasonal homes along Old River Rd. Water is at the base of the Caledonia/Lewiston Levee near Old River Rd. In the Town of Dekorra, water is over portions of River Oaks Rd. and Oak Knoll Dr., while about a dozen homes are flooded on Hwy V. |
| May 2017 | Flood | Portage | $5,000 | The Wisconsin River near Portage reached moderate flood stage, eventually cresting at 18.30 feet. Widespread flooding of the Blackhawk Park and Long Lake areas occurred with many flooded roads and road closures in that area. Some seasonal homes along Old River Road were surrounded by floodwaters. Farther south in the Town of Dekorra, a few homes had floodwaters in the first floor along with the flooding of outbuildings. Floodwaters also flowed over County Highway V and River Oaks Road in the Town of Dekorra. Some residents had to use canoes or boats for transportation to and from their homes throughout the flooded area. |
| December 2015 | Flood | Portage | $5,000 | The Wisconsin River near Portage reached flood stage and flooded much of the Blackhawk Park area and near Long Lake on the south side of the river from Portage. A few roads were closed including Old River Road and West Lane Road with around 4 feet of water over them. Some seasonal homes along Old River Road were surrounded by floodwaters. Farther south in the Town of Dekorra, a few homes had floodwaters in the first floor along with the flooding of outbuildings. Floodwaters also flowed over County Highway J in the Town of Dekorra. Some residents had to use canoes or boats for transportation to and from their homes. |
| December 2014 | Flood | Portage | $5,000 | An ice jam caused the Wisconsin River at Portage to rise above flood stage at 17.08 feet for a brief period. Minor lowland flooding was already occurring from late November and continued well into December. This caused flooding of the lower roads in the Blackhawk Park area, which is between the Wisconsin River and Long Lake. The roads were closed with a few feet of water and ice on the roads. The water and ice is very near to several small homes with a small number of people having to canoe or walk to dry land. |
| July 2007 | Thunderstorm Wind | Portage | $5,000 | Powerful downburst thundestorm winds gusting to around 52 knots (60 mph) toppled large trees. A couple power-lines came down with tree debris. |
| July 2006 | Thunderstorm Wind | Portage | $5,000 | Trees and power-lines reported down. |
| July 1999 | Thunderstorm Wind | Portage | $5,000 | The Sauk County severe storm pulsed up once again and flattened many large trees and some corn crop. |
| July 2005 | Thunderstorm Wind | Portage | $5,000 | no account filed |
| July 1996 | Thunderstorm Wind | Portage | $5,000 | no account filed |
| March 2000 | Hail | Portage | $4,000 | no account filed |
| June 1998 | Thunderstorm Wind | Portage | $4,000 | no account filed |
| April 2025 | Flood | Portage | $3,000 | Water surrounds seasonal homes along Old River Rd. in the Blackhawk Park area including water at the base of Caledonia/Lewiston Levee on Old River Rd. Old River Rd, W. Lake Rd, Sec K Rd., Blackhawk Rd. are covered with water. West Lane Rd. in the Long Lake area has 4 feet of water over it in places. In the Town of Dekorra, about 12 homes are flooded on Hwy V. Water is over River Oaks Rd. and Oak Knoll Dr. near Hwy V. |
| August 2020 | Thunderstorm Wind | Portage | $3,000 | Several trees down or snapped off in the Saddle Ridge Estates neighborhood. |
| April 2019 | Flood | Portage | $3,000 | The Wisconsin River at Portage crested at minor flood stage in late March and continued into early April. In the Blackhawk Park area in the Town of Caledonia, Wood St. is affected by floodwaters. Old River Rd. and Blackhawk Rd. is flooded and closed. Near Long Lake, West Lane Rd. and West Lake Rd. are flooded and closed. County Highway V and Oak Knoll Road in the Town of Dekorra have water up to the edge of the pavement. A few homes in the Town of Dekorra have water in the first floor, and there is also flooding of outbuildings and yards. |
| June 2018 | Thunderstorm Wind | Portage | $3,000 | Several trees down in and around Portage. |
| August 2018 | Thunderstorm Wind | Portage | $3,000 | Several trees and power lines down. |
| April 2025 | Flood | Portage | $2,000 | Water surrounds seasonal homes along Old River Rd. in the Blackhawk Park area including water at the base of Caledonia/Lewiston Levee on Old River Rd. Old River Rd, W. Lake Rd, Sec K Rd., Blackhawk Rd. are covered with water. West Lane Rd. in the Long Lake area has 4 feet of water over it in places. In the Town of Dekorra, several homes on Hwy V have water on the 1st floor. Water is partially over River Oaks Rd. and Oak Knoll Dr. near Hwy V. |
| July 2017 | Thunderstorm Wind | Portage | $2,000 | A few trees down near Portage. |
| May 2007 | Thunderstorm Wind | Portage | $2,000 | Large trees were uprooted. |
| June 1998 | Thunderstorm Wind | Portage | $2,000 | no account filed |
| May 1998 | Thunderstorm Wind | Portage | $2,000 | no account filed |
| July 1997 | Thunderstorm Wind | Portage | $2,000 | no account filed |
| August 2025 | Thunderstorm Wind | Portage | $1,000 | Large tree uprooted along Highway 16 in Portage. A branch down in the city. |
| September 2025 | Flood | Portage | $1,000 | Multiple reports of minor street flooding in the city of Portage. |
| October 2019 | Flash Flood | Portage | $1,000 | Street flooding across Portage including Henry Dr. and Winnebago St. |
| June 2018 | Flood | Portage | $1,000 | There is general overflow of the river. Water is near homes in the Blackhawk Park area of Portage on the south side of the river along Old River Road. Floodwaters are over West Lake Road and Blackhawk Road in the Blackhawk Park area. Floodwaters are over West Lane Road in the Long Lake area. |
| August 2006 | Heavy Rain | Portage | $1,000 | Persistent heavy rain caused some basement flooding 3 miles north of Portage. |
| March 2000 | Hail | Portage | $1,000 | no account filed |
| May 2000 | Thunderstorm Wind | Portage | $1,000 | no account filed |
| May 2025 | Tornado (EFU) | Portage | - | No damage was found due to the tornado occurring in the Baraboo River Waterfowl Protection area south of Portage. Video from Portage Fire Department and reports from multiple storm chasers and spotters show a brief tornado occurring south of Portage. |
| August 2021 | Thunderstorm Wind | Portage | - | Wind speeds were estimated by trained spotter. Branches were downed and a house was struck by lightning in the area. |
| October 2013 | Heavy Rain | Portage | - | High standing water on some streets. |
| June 2008 | Flash Flood | Portage | - | Heavy rains resulted in a flash flood event on June 7th that allowed water to cover Interstate 90/94 near STH 78. Consequently, the Interstate had to be closed. This event was one of 3 flash flood events over parts of Columbia County on 3 separate days. Two started on June 7th, one on June 8th. In all 3 flash flood events, home and business damage was reported, and there was crop damage. It was nearly impossible to break down the damages by flash flood. Therefore, the collective damage breakdown for these events is provided in the June 8th flash flood StormData entry for Columbia County. |