Polk County, Wisconsin Natural Disaster Risk
FEMA National Risk Index assessment · WI
LowComposite Risk Score
National percentile: 63th
Polk County faces low composite natural disaster risk (NRI Risk Index score 63.3, 63th national percentile), driven primarily by cold wave and strong wind exposure. Expected annual loss across all 18 hazard types is $23M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Polk County carries a low composite natural disaster risk, with a National Risk Index score of 63.3 out of 100 — placing it in the 63rd 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.
The county's risk is driven primarily by cold wave (prolonged spells of dangerously low temperatures) at High risk — $7M in expected annual loss and about 9.47 events per year; strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at High risk — $2M in expected annual loss and about 3.21 events per year; and hail (ice stones from severe thunderstorms that damage property and crops) at Medium risk — $2M in expected annual loss and about 4.47 events per year. Across all hazards, FEMA estimates $23M in expected annual loss for a population of 45K.
Beyond physical exposure, Polk County has a 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.
History supports the rating: Polk County has received 10 federal disaster declarations since 1965, including 2 for biological events and 2 for flood events. The most recent was Covid-19 Pandemic (biological), declared in April 2020.
Among 72 Wisconsin counties, Polk County ranks #34 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Cold Wave | High | 9.47 / yr | $7M |
| Strong Wind | High | 3.21 / yr | $2M |
| Hail | Medium | 4.47 / yr | $2M |
| Tornado | Medium | 0.44 / yr | $3M |
| Lightning | Medium | 33.37 / yr | $513K |
| Heat Wave | Low | 2.00 / yr | $571K |
| Winter Weather | Low | 17.05 / yr | $79K |
| Riverine Flood | Low | 0.36 / yr | $8M |
| Ice Storm | Low | 0.34 / yr | $62K |
| Wildfire | Very Low | 0.00 / yr | $29K |
| Drought | Very Low | 2.25 / yr | $17K |
| Landslide | Very Low | 0.26 / yr | $107 |
| 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
Polk County has received 10 federal disaster declarations since 1965, most recently Covid-19 Pandemic in April 2020. Most frequent causes: Biological (2), Flood (2), Tornado (2).
| Declared | Type | Disaster |
|---|---|---|
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| August 2019 | Flood | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| September 2002 | Tornado | Severe Storms, Tornadoes and Flooding |
| May 2001 | Flood | Flooding, Severe Storms and Tornadoes |
| June 2000 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| October 1977 | Severe Storm | Winds, Hail & Rain |
| June 1976 | Drought | Drought |
| April 1965 | Tornado | Tornadoes, Severe Storms & Flooding |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Polk County?
Polk County has a composite FEMA National Risk Index score of 63.3 out of 100, placing it in the Low category and the 63th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Polk County?
The three highest-rated hazards are Cold Wave (High, $7M EAL), Strong Wind (High, $2M EAL), Hail (Medium, $2M EAL). These account for most of the county's expected annual losses.
How does Polk County compare to other Wisconsin counties?
Polk County ranks #34 of 72 Wisconsin counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Polk County had?
FEMA records 10 federal disaster declarations for Polk County since 1965, most often 2 for biological events and 2 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. Polk County's $23M EAL is a statistical average, not a guarantee for any specific year or address.