Dunn County, Wisconsin Natural Disaster Risk
FEMA National Risk Index assessment · WI
LowComposite Risk Score
National percentile: 49th
Dunn County faces low composite natural disaster risk (NRI Risk Index score 48.8, 49th national percentile), driven primarily by landslide and strong wind exposure. Expected annual loss across all 18 hazard types is $22M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Dunn County at low composite risk, with a National Risk Index score of 48.8 out of 100 — placing it in the 49th 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.
Most of Dunn County's expected losses come from landslide (downhill movement of rock, soil, and debris on unstable slopes) at Low risk — $37K in expected annual loss and about 0.39 events per year; strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at Medium risk — $2M in expected annual loss and about 3.25 events per year; and hail (ice stones from severe thunderstorms that damage property and crops) at Medium risk — $1M in expected annual loss and about 4.18 events per year. Across all hazards, FEMA estimates $22M in expected annual loss for a population of 45K.
Beyond physical exposure, Dunn County has a very low social vulnerability rating (how susceptible the population is to harm) and a medium community resilience rating (its capacity to prepare for and recover from disasters). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
The county's disaster history tells the same story: Dunn County has received 13 federal disaster declarations since 1965, including 4 for flood events and 3 for severe storm events. The most recent was Covid-19 Pandemic (biological), declared in April 2020.
Among 72 Wisconsin counties, Dunn County ranks #50 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | Low | 0.39 / yr | $37K |
| Strong Wind | Medium | 3.25 / yr | $2M |
| Hail | Medium | 4.18 / yr | $1M |
| Cold Wave | Medium | 8.84 / yr | $5M |
| Tornado | Medium | 0.45 / yr | $3M |
| Lightning | Medium | 34.63 / yr | $563K |
| Heat Wave | Low | 2.89 / yr | $662K |
| Riverine Flood | Low | 0.57 / yr | $10M |
| Winter Weather | Low | 16.79 / yr | $74K |
| Ice Storm | Low | 0.42 / yr | $59K |
| Drought | Very Low | 2.34 / yr | $3K |
| Wildfire | Very Low | 0.00 / yr | $6K |
| Earthquake | Very Low | 0.00 / yr | $7K |
| 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
Dunn County has received 13 federal disaster declarations since 1965, most recently Covid-19 Pandemic in April 2020. Most frequent causes: Flood (4), Severe Storm (3), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| September 2002 | Tornado | Severe Storms, Tornadoes and Flooding |
| July 2002 | 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 |
| July 1980 | Flood | Severe Storms & Flooding |
| June 1976 | Drought | Drought |
Showing the 10 most recent of 13 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Dunn County?
Dunn County has a composite FEMA National Risk Index score of 48.8 out of 100, placing it in the Low category and the 49th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Dunn County?
The three highest-rated hazards are Landslide (Low, $37K EAL), Strong Wind (Medium, $2M EAL), Hail (Medium, $1M EAL). These account for most of the county's expected annual losses.
How does Dunn County compare to other Wisconsin counties?
Dunn County ranks #50 of 72 Wisconsin counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Dunn County had?
FEMA records 13 federal disaster declarations for Dunn County since 1965, most often 4 for flood events and 3 for severe storm 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. Dunn County's $22M EAL is a statistical average, not a guarantee for any specific year or address.