Trempealeau County, Wisconsin Natural Disaster Risk
FEMA National Risk Index assessment · WI
LowComposite Risk Score
National percentile: 59th
Trempealeau County faces low composite natural disaster risk (NRI Risk Index score 58.7, 59th national percentile), driven primarily by landslide and hail exposure. Expected annual loss across all 18 hazard types is $20M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Trempealeau County is low, with a National Risk Index score of 58.7 out of 100 — placing it in the 59th national percentile and below the national average for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in landslide (downhill movement of rock, soil, and debris on unstable slopes) at Medium risk — $58K in expected annual loss and about 0.72 events per year; hail (ice stones from severe thunderstorms that damage property and crops) at Medium risk — $1M in expected annual loss and about 3.71 events per year; and cold wave (prolonged spells of dangerously low temperatures) at Medium risk — $3M in expected annual loss and about 7.84 events per year. Across all hazards, FEMA estimates $20M in expected annual loss for a population of 31K.
Beyond physical exposure, Trempealeau County has a medium social vulnerability rating (how susceptible the population is to harm) and a high community resilience rating (its capacity to prepare for and recover from disasters). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
History supports the rating: Trempealeau County has received 15 federal disaster declarations since 1965, including 7 for severe storm events and 3 for flood events. The most recent was Covid-19 Pandemic (biological), declared in April 2020.
Among 72 Wisconsin counties, Trempealeau County ranks #42 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | Medium | 0.72 / yr | $58K |
| Hail | Medium | 3.71 / yr | $1M |
| Cold Wave | Medium | 7.84 / yr | $3M |
| Lightning | Medium | 35.43 / yr | $621K |
| Riverine Flood | Low | 2.82 / yr | $12M |
| Strong Wind | Medium | 3.08 / yr | $816K |
| Heat Wave | Low | 3.37 / yr | $587K |
| Tornado | Low | 0.30 / yr | $2M |
| Ice Storm | Low | 0.33 / yr | $71K |
| Winter Weather | Low | 16.47 / yr | $49K |
| Drought | Low | 4.20 / yr | $55K |
| Wildfire | Very Low | 0.00 / yr | $4K |
| Earthquake | Very Low | 0.00 / yr | $5K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Trempealeau County has received 15 federal disaster declarations since 1965, most recently Covid-19 Pandemic in April 2020. Most frequent causes: Severe Storm (7), Flood (3), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| October 2017 | Severe Storm | Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mud |
| October 2010 | Severe Storm | Severe Storms and Flooding |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| June 2004 | Severe Storm | Severe Storms and Flooding |
| May 2001 | Flood | Flooding, Severe Storms and Tornadoes |
| July 1998 | Severe Storm | Severe Storms,Straigh Line Winds, Tornadoes,Rain,and Floodi |
| July 1993 | Severe Storm | Severe Storms, Tornadoes & Flooding |
| September 1992 | Flood | Severe Storms & Flooding |
Showing the 10 most recent of 15 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Trempealeau County?
Trempealeau County has a composite FEMA National Risk Index score of 58.7 out of 100, placing it in the Low category and the 59th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Trempealeau County?
The three highest-rated hazards are Landslide (Medium, $58K EAL), Hail (Medium, $1M EAL), Cold Wave (Medium, $3M EAL). These account for most of the county's expected annual losses.
How does Trempealeau County compare to other Wisconsin counties?
Trempealeau County ranks #42 of 72 Wisconsin counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Trempealeau County had?
FEMA records 15 federal disaster declarations for Trempealeau County since 1965, most often 7 for severe storm events and 3 for flood events. The most recent was Covid-19 Pandemic, declared in April 2020.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Trempealeau County's $20M EAL is a statistical average, not a guarantee for any specific year or address.