Washington County Disaster Risk

Washington County has a FEMA National Risk Index rating of Relatively High, placing it in the 96th percentile nationally out of 3,144 counties. This composite score reflects the county's overall exposure to natural hazards including floods, wildfires, tornadoes, earthquakes, and hurricanes, weighted by expected annual loss and social vulnerability.

Washington County is evaluated for five major natural hazard types: earthquake (99th percentile), flooding (94th percentile), tornado (53th percentile), wildfire (51th percentile). The highest-risk hazard is earthquake at the 99th percentile nationally. These scores are derived from FEMA's National Risk Index, which analyzes expected annual loss, social vulnerability, and community resilience for each hazard type.

Washington County's composite risk percentile is 96th, compared to the Oregon state average of 63th percentile. The state's overall risk rating is Relatively Low. This means Washington County faces higher natural disaster risk than the typical county in Oregon.

Yes, Washington County's earthquake risk is at the 99th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Washington County is at the 94th percentile.

FEMA's National Risk Index (NRI) calculates risk scores for 18 natural hazard types across all U.S. counties and census tracts. The composite score combines Expected Annual Loss (estimated dollar losses from each hazard), Social Vulnerability (demographic factors affecting disaster impact), and Community Resilience (ability to recover). Percentile scores rank each county against all 3,144 U.S. counties, and risk ratings range from Very Low to Very High.

Washington County's composite risk score of 96th percentile is above the Oregon state average of 63th percentile. This elevated risk is driven by earthquake exposure (99th percentile), along with flooding and tornado and wildfire risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.