Washington County
Oregon — Natural Disaster Risk Assessment
HighComposite Risk Score
National percentile: 96th
Washington County faces high composite natural disaster risk (NRI Risk Index score 96.0, 96th national percentile), driven primarily by earthquake and heat wave exposure. Expected annual loss across all 18 hazard types is $270M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Earthquake | High | 0.01 / yr | $163M |
| Heat Wave | High | 6.25 / yr | $11M |
| Riverine Flood | High | 0.75 / yr | $81M |
| Ice Storm | High | 1.22 / yr | $1M |
| Cold Wave | High | 0.23 / yr | $9M |
| Volcanic Activity | Low | 0.01 / yr | $16K |
| Landslide | Low | 3.91 / yr | $43K |
| Lightning | Medium | 5.88 / yr | $1M |
| Strong Wind | Medium | 0.05 / yr | $2M |
| Winter Weather | Medium | 10.65 / yr | $216K |
| Tornado | Low | 0.07 / yr | $2M |
| Wildfire | Very Low | 0.00 / yr | $65K |
| Hail | Very Low | 0.05 / yr | $151K |
| Drought | Very Low | 0.19 / yr | $0 |
| Avalanche | Very Low | 0.01 / yr | $11 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Frequently Asked Questions
What is the overall natural disaster risk for Washington County?
Washington County has a composite FEMA National Risk Index score of 96.0 out of 100, placing it in the High category and the 96th 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 Earthquake (High, $163M EAL), Heat Wave (High, $11M EAL), Riverine Flood (High, $81M EAL). These account for most of the county's expected annual losses.
How does Washington County compare to other Oregon counties?
Washington County ranks #3 of 36 Oregon counties for overall natural disaster risk, with a high rating.
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 $270M EAL is a statistical average, not a guarantee for any specific year or address.