Washington County, Wisconsin Natural Disaster Risk
FEMA National Risk Index assessment · WI
LowComposite Risk Score
National percentile: 68th
Washington County faces low composite natural disaster risk (NRI Risk Index score 68.3, 68th national percentile), driven primarily by cold wave and hail exposure. Expected annual loss across all 18 hazard types is $48M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Washington County carries a low composite natural disaster risk, with a National Risk Index score of 68.3 out of 100 — placing it in the 68th 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 — $13M in expected annual loss and about 5.42 events per year; hail (ice stones from severe thunderstorms that damage property and crops) at Medium risk — $2M in expected annual loss and about 3.20 events per year; and tornado (violently rotating columns of air capable of catastrophic local damage) at Medium risk — $9M in expected annual loss and about 0.28 events per year. Across all hazards, FEMA estimates $48M in expected annual loss for a population of 137K.
Beyond physical exposure, Washington County has a very 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.
History supports the rating: Washington County has received 14 federal disaster declarations since 1976, including 4 for flood events and 4 for severe storm events. The most recent was Severe Storms, Tornadoes, and Flooding (flood), declared in June 2026.
Among 72 Wisconsin counties, Washington County ranks #30 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Cold Wave | High | 5.42 / yr | $13M |
| Hail | Medium | 3.20 / yr | $2M |
| Tornado | Medium | 0.28 / yr | $9M |
| Heat Wave | Low | 2.74 / yr | $2M |
| Riverine Flood | Low | 0.61 / yr | $20M |
| Winter Weather | Medium | 15.68 / yr | $183K |
| Landslide | Very Low | 0.11 / yr | $5K |
| Lightning | Medium | 33.91 / yr | $577K |
| Strong Wind | Medium | 3.43 / yr | $1M |
| Wildfire | Very Low | 0.00 / yr | $80K |
| Ice Storm | Low | 0.48 / yr | $68K |
| Drought | Low | 0.55 / yr | $61K |
| Earthquake | Very Low | 0.00 / yr | $169K |
| Hurricane | Very Low | 0.01 / yr | $3K |
| 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
Washington County has received 14 federal disaster declarations since 1976, most recently Severe Storms, Tornadoes, and Flooding in June 2026. Most frequent causes: Flood (4), Severe Storm (4), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| June 2026 | Flood | Severe Storms, Tornadoes, and Flooding |
| September 2025 | Flood | Severe Storms, Straight-Line Winds, Flooding, and Mudslides |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| April 2011 | Snowstorm | Severe Winter Storm and Snowstorm |
| June 2008 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| March 2008 | Snowstorm | Record Snow and Near Record Snow |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| June 2004 | Severe Storm | Severe Storms and Flooding |
| July 1997 | Severe Storm | Severe Storms and Flooding |
Showing the 10 most recent of 14 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Washington County?
Washington County has a composite FEMA National Risk Index score of 68.3 out of 100, placing it in the Low category and the 68th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Washington County?
The three highest-rated hazards are Cold Wave (High, $13M EAL), Hail (Medium, $2M EAL), Tornado (Medium, $9M EAL). These account for most of the county's expected annual losses.
How does Washington County compare to other Wisconsin counties?
Washington County ranks #30 of 72 Wisconsin counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Washington County had?
FEMA records 14 federal disaster declarations for Washington County since 1976, most often 4 for flood events and 4 for severe storm 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. Washington County's $48M EAL is a statistical average, not a guarantee for any specific year or address.