Washington County Disaster Risk
Washington County, Oregon
FEMA Risk Rating
Relatively High
National Percentile
96th
of 3,144 counties
State Rank
#3
of 36 (1 = highest risk)
Flood Risk
94th
percentile
Hazard Risk Breakdown
Flood
River, coastal, and surface flooding risk
Moderate
Higher than 94% of US counties
Wildfire
Wildland and wildland-urban interface fire risk
Relatively Low
Higher than 51% of US counties
Tornado
Tornado and severe thunderstorm risk
Relatively Low
Higher than 53% of US counties
Earthquake
Seismic activity and ground shaking risk
Relatively High
Higher than 99% of US counties
Risk Overview
About Natural Disaster Risk in Washington County, Oregon
Washington County faces high national disaster risk
Washington County scores 96.02 on the composite risk scale, placing it firmly in the Relatively High category and well above the national median. This score signals that Washington residents face notably elevated exposure to multiple serious natural hazards.
Highest-risk county in Oregon
At 96.02, Washington County significantly exceeds Oregon's state average composite risk of 63.43, making it one of the state's most hazard-prone counties. This elevated standing reflects compounded exposure across multiple disaster types, not weakness in any single category.
Washington County's flood risk stands apart
Washington's flood risk score of 93.86 dramatically exceeds its neighbors: Yamhill County (74.11) and Wasco County (59.22). While earthquake risk is comparable across the region (Washington 99.01, Yamhill 96.88, Wasco 82.98), Washington's exceptionally high flood exposure makes it uniquely vulnerable in the tri-county area.
Floods and earthquakes pose acute threats
Washington County faces a severe flood risk of 93.86—driven by its extensive river systems, urban development in floodplains, and heavy winter rainfall—making it the county's most dangerous hazard. Earthquake risk ranks close behind at 99.01, reflecting proximity to the Cascadia Subduction Zone and indicating that major seismic activity poses an existential threat to structures and infrastructure.
Flood and earthquake insurance are essential
Washington County residents must secure flood insurance immediately—standard homeowners policies exclude flood damage, and federal data shows many residents in high-risk zones remain uninsured. Paired with mandatory earthquake coverage, a comprehensive protection strategy addresses Washington County's dual crisis of water and seismic hazards.
Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor
Preparedness Guide
What to Prepare for in Washington County
Top Hazards by Exposure
Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)
Risk Advisory: Washington County
Risk Verdict
With a national rank of 96th percentile, Washington County faces above-average natural disaster pressure across several hazard categories. High composite risk signals that multiple hazard types are elevated simultaneously; planning for more than one scenario is important in Washington County.
Hazard Breakdown
Earthquake risk is Washington County's dominant natural hazard, ranked at the 99th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 94th percentile nationally. Additional tracked hazards include tornado (53th percentile), wildfire (51th percentile).
Preparedness Context
Washington County's primary hazard, earthquake, ranks at the 99th percentile nationally. Unreinforced masonry structures carry the highest injury risk during seismic events; residents in older buildings should check with their municipality about available seismic retrofit programs. Alongside earthquake exposure, Washington County's flood risk at the 94th percentile nationally reinforces the value of maintaining a household emergency supply cache usable for multiple hazard scenarios. After a major earthquake, Washington County residents should expect water service disruption for 24 to 72 or more hours. Storing a minimum of one gallon per person per day for three days — before any event — is the most direct preparedness action households can take.
Regional Context
Washington County falls 32.6 points above Oregon's typical county risk level, which means the hazard environment here is notably more demanding than the state baseline.
Is your household prepared for Washington County's hazards?
Review FEMA's county-specific preparedness checklists and emergency planning guides.
Frequently Asked Questions
What is the natural disaster risk in Washington County, OR?
What types of natural hazards affect Washington County?
How does Washington County risk compare to the Oregon average?
Is Washington County at risk for earthquake?
How is natural disaster risk measured?
Why is Washington County higher risk than average?
Data Source
Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.
Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.