Winnebago County, Wisconsin Natural Disaster Risk
FEMA National Risk Index assessment · WI
MediumComposite Risk Score
National percentile: 87th
Winnebago County faces medium composite natural disaster risk (NRI Risk Index score 86.8, 87th national percentile), driven primarily by cold wave and strong wind exposure. Expected annual loss across all 18 hazard types is $75M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Winnebago County is medium, with a National Risk Index score of 86.8 out of 100 — placing it in the 87th national percentile and near the national midpoint 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 cold wave (prolonged spells of dangerously low temperatures) at High risk — $14M in expected annual loss and about 5.74 events per year; strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at High risk — $3M in expected annual loss and about 2.96 events per year; and hail (ice stones from severe thunderstorms that damage property and crops) at Medium risk — $3M in expected annual loss and about 2.78 events per year. Across all hazards, FEMA estimates $75M in expected annual loss for a population of 172K.
Beyond physical exposure, Winnebago County has a low social vulnerability rating (how susceptible the population is to harm) and a very 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.
The county's disaster history tells the same story: Winnebago County has received 11 federal disaster declarations since 1974, including 4 for severe storm events and 2 for flood events. The most recent was Severe Storms, Tornadoes, and Flooding (flood), declared in June 2026.
Among 72 Wisconsin counties, Winnebago County ranks #6 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Cold Wave | High | 5.74 / yr | $14M |
| Strong Wind | High | 2.96 / yr | $3M |
| Hail | Medium | 2.78 / yr | $3M |
| Tornado | High | 0.34 / yr | $9M |
| Riverine Flood | Medium | 0.57 / yr | $43M |
| Lightning | High | 34.17 / yr | $989K |
| Winter Weather | Medium | 15.63 / yr | $218K |
| Heat Wave | Low | 1.63 / yr | $1M |
| Ice Storm | Low | 0.27 / yr | $99K |
| Wildfire | Very Low | 0.00 / yr | $31K |
| Earthquake | Very Low | 0.00 / yr | $116K |
| Drought | Very Low | 0.69 / yr | $18K |
| Landslide | Very Low | 0.05 / yr | $157 |
| Hurricane | Very Low | 0.01 / yr | $5K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Winnebago County has received 11 federal disaster declarations since 1974, most recently Severe Storms, Tornadoes, and Flooding in June 2026. Most frequent causes: Severe Storm (4), Flood (2), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| June 2026 | Flood | Severe Storms, Tornadoes, and Flooding |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| June 2008 | Severe Storm | Severe Storms, Tornadoes, 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 1993 | Severe Storm | Severe Storms, Tornadoes & Flooding |
| July 1990 | Severe Storm | Severe Storms, Tornadoes & Flooding |
| June 1976 | Drought | Drought |
Showing the 10 most recent of 11 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Winnebago County?
Winnebago County has a composite FEMA National Risk Index score of 86.8 out of 100, placing it in the Medium category and the 87th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Winnebago County?
The three highest-rated hazards are Cold Wave (High, $14M EAL), Strong Wind (High, $3M EAL), Hail (Medium, $3M EAL). These account for most of the county's expected annual losses.
How does Winnebago County compare to other Wisconsin counties?
Winnebago County ranks #6 of 72 Wisconsin counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Winnebago County had?
FEMA records 11 federal disaster declarations for Winnebago County since 1974, most often 4 for severe storm events and 2 for flood events. The most recent was Severe Storms, Tornadoes, and Flooding, declared in June 2026.
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. Winnebago County's $75M EAL is a statistical average, not a guarantee for any specific year or address.