Onalaska

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond this area.
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.

Flood insurance figures are for La Crosse County, the county that contains Onalaska.

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.

River crests

River gauges in La Crosse County, the county that contains Onalaska.

River gauges

1. Crests are the highest and the recent crests the National Weather Service lists for each river gauge in the county that has a flood stage, not every flood. Flood categories use each gauge's current flood stages; crests from before levees, dams or channel changes may not be comparable. Crests measured on an old datum are left out of the rankings.

NOAA National Water Prediction Service gauge records, retrieved October 30, 2026.

The drought index is for La Crosse County, the county that contains Onalaska.

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.

Mapped landslides

Landslides mapped in La Crosse County.

Mapped by NASA (2).

1. Landslides mapped in the USGS compilation of landslide inventories across the United States (version 3.0, 2025), rated probable or better. The compilation joins inventories made by federal and state agencies for different purposes and areas, so the number mapped in a county reflects how closely it has been surveyed as much as how often its slopes fail. An area with few records may simply not have been mapped. Deaths are as recorded in the inventories; a slide listed in two inventories is counted once.

USGS Landslide Inventories across the United States, version 3.0, retrieved October 27, 2026.

More event types since 1996

Costliest events since 1996

1. Jun 2, 2020Hail$45.5 million
   National Weather Service narrative

   Hail ranging in size from 1 inch upto 2.5 inches in diameter fell in Holmen. Most of the hail was golf ball sized or larger. Between 4,000 and 5,000 homes sustained roof damage from the hail.

2. Apr 10, 2011Hail$20.0 million
   National Weather Service narrative

   Hundreds of homes received roof and siding damage as well as broken windows on the south side of La Crosse. Wal Mart department store reported approximately 20 sky lights broken. Hundreds of cars were also damaged with dents and broken windows and mirrors. There were several thousand claims made to major insurance companies in and around the La Crosse area.

3. May 22, 2011Tornado$15.2 million
   National Weather Service narrative

   This tornado originally began in Houston County Minnesota and crossed into La Crosse near Target Lake. The first damage occurred on Green Island where numerous mature trees were snapped off and substantial damage occurred to the Green Island ice arena. The tornado then moved into a residential area where buildings sustained partial roof removal and garages were heavily damaged. Buildings in a small industrial area near the intersection of Green Bay Street and West Ave had walls partially collapse causing the roofs to subsequently collapse and a small apartment complex had its roof cleanly removed. After this, the tornado tracked primarily through residential areas until it…

4. Aug 18, 2007Flash Flood$11.9 million
   National Weather Service narrative

   Heavy rain led to major flash flooding in the south end of the county, especially south of La Crosse. Mudslides were reported along Highways 35 and 33. There was also major street flooding and water in basements. Parts of a retaining wall washed away at the intersection of Highways 14, 61, and 35 and erosion washed away some smaller roads.||About 644 people applied for FEMA assistance.

5. Apr 10, 2011Hail$5.0 million
   National Weather Service narrative

   A cold front pushed east into Wisconsin during the late afternoon and evening hours of April 10th. Severe thunderstorms developed along the cold front and produced very large hail and three tornadoes over portions of western and central Wisconsin. The hail ranged from quarter to tennis ball size and caused extensive damage to siding and cars in the southern portions of the city of La Crosse (La Crosse County). Although difficult to estimate, damage estimates from insurance companies and contractors in the area were between 20 and 30 million dollars from the one hail storm. National Weather Service storm survey teams confirmed two EF1 tornadoes and an EF2 tornado in Juneau and…

6. Jul 20, 2017Flash Flood$2.6 million
   National Weather Service narrative

   Heavy rains, with totals of 6 to 8 inches, produced flash flooding across La Crosse County. The Shelby Fire Department had to evacuate people along County Road M in the township of Greenfield. Some of these evacuations had to be made by boat. Other rescues had to be made along Kammell Coulee Road southeast of St. Joseph. County Road U was closed between Bangor and Rockland due to flooding along Fish Creek. Flood waters along Mormon Creek washed out the approaches to both sides of a bridge on Breidel Coulee Road south of Barre Mills. Some streets in Onalaska were washed out or completely underwater. Numerous streets in the city of La Crosse were underwater causing a giant sinkhole…

7. Jul 20, 2017Flood$2.3 million
   National Weather Service narrative

   After the initial round of flash flooding, the flood waters continued to cause problems into Friday, July 21st. Numerous roads across the county remained closed until the flood waters receded.

8. Jun 2, 2020Hail$2.1 million
   National Weather Service narrative

   Hail up to 2.5 inches in diameter fell in New Amsterdam.

9. May 1, 2001Flood, La Crosse$1.7 million
   National Weather Service narrative

   The Mississippi River crested in April 2001 at levels second only to the all-time flood of record, which occurred in April 1965. Even though water levels were receding, the river remained above flood stage, which continued flooding until the middle of May. High water levels caused damage to homes and businesses, especially in the Prairie du Chien area (Crawford County) and points southward. Due to the extensive damage caused by flood waters, Buffalo, Trempealeau, La Crosse, Vernon, Crawford and Grant County received federal disaster relief funds.

10. Apr 12, 2001Flood, La Crosse$1.5 million
    National Weather Service narrative

    Heavy rains, combined with snow melt runoff, caused the Mississippi River to reach near record levels. In fact, at most locations the water reached levels second only to the all-time flood of record, which occurred in April 1965. The Mississippi River at La Crosse (La Crosse County) crested at 16.4 feet on April 18, which was the third all-time highest flood on record. Hardest hit was the Prairie du Chien area (Crawford County) and points southward, where flood waters did considerable damage to businesses and homes. Overall damage due to the high water was estimated around 6 million dollars. This resulted in Buffalo, Trempealeau, La Crosse, Vernon, Crawford and Grant County being…

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

108°FJul 13, 1995

All-time low

−37°FJan 30, 1951

Warmest night

81°F3 times, most recently Jun 30, 2026

Coldest day

−18°FDec 23, 1983

Wettest day

5.59 inAug 7, 2021

Snowiest day

14.4 inDec 3, 1990

Hottest year

1998mean 51.9°F

Coldest year

1950mean 42.4°F

Wettest year

201644.76 in

Driest year

194816.74 in

Snowiest season

78.7 in1961-62

Station La Crosse Municipal Airport (USW00014920), 650 ft elevation, 2.5 miles from the city centre. Daily records from 1938 to October 27, 2026; 100.0% 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.

Declarations for La Crosse County.

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.

• 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 USW00014920.
• 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.
• Landslides USGS Landslide Inventories across the United States, version 3.0 (2025).
• 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.