riskbycounty
FEMA NRI 1.19.0Updated Nov 2023 · Coverage 2014–2023Methodology

Thurston County Disaster Risk

Thurston County, Washington

FEMA Risk Rating

Relatively High

National Percentile

94th

of 3,144 counties

State Rank

#5

of 39 (1 = highest risk)

Flood Risk

91th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Moderate

Higher than 91% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Relatively Low

Higher than 57% of US counties

Tornado

Tornado and severe thunderstorm risk

Very Low

Higher than 25% 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 Thurston County, Washington

Thurston County faces significant disaster risk

Thurston County scores 94.50 on the national composite risk scale, earning a Relatively High rating and exceeding Washington's state average of 70.01 by 35 percent. This places Olympia's home county among the more hazard-exposed regions in the nation.

One of Washington's highest-risk counties

Thurston County ranks near the top of Washington's disaster risk hierarchy, with a composite score of 94.50 that trails only a handful of counties in the state. Its elevated exposure stems from a potent combination of earthquake, flood, and moderate wildfire threats.

Riskier than most surrounding areas

Thurston County's risk score of 94.50 significantly exceeds neighbors like Lewis County and Pacific County, placing it as the most hazard-exposed county in its region. Only Whatcom County to the north (90.97) comes close to Thurston's comprehensive risk profile.

Earthquakes and floods drive exposure

Earthquake risk reaches 98.92 in Thurston County—among the nation's highest—reflecting its proximity to the Puget Sound Subduction Zone and Cascadia fault system. Flood risk of 90.81 adds significant exposure through Nisqually River flooding and coastal surge impacts in lower elevations.

Earthquake and flood insurance essential

Thurston County residents must secure comprehensive earthquake insurance, as standard homeowners policies exclude seismic damage and recovery can be catastrophic. Flood insurance is equally critical, particularly for homes in river valleys or areas with poor drainage; review FEMA flood maps and upgrade your policy limits.

Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor

Preparedness Guide

What to Prepare for in Thurston County

Top Hazards by Exposure

  1. #1
    EarthquakePrepare
    99th percentile
  2. #2
    FloodPrepare
    91th percentile
  3. #3
    WildfirePrepare
    57th percentile

Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)

Local Resources

Risk Advisory: Thurston County

Risk Verdict

Thurston County carries an elevated natural disaster risk burden, scoring at the 94th percentile nationally under FEMA's risk model. This risk level calls for more than general awareness: insurance coverage review, a family communication plan, and a prepared go-bag are practical priorities.

Hazard Breakdown

Earthquake risk is Thurston County's dominant natural hazard, ranked at the 99th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 91th percentile nationally. Additional tracked hazards include wildfire (57th percentile), tornado (25th percentile).

Preparedness Context

Earthquake risk is Thurston County's leading natural hazard, ranked at the 99th percentile nationally. Securing tall furniture, water heaters, and bookcases to walls with anti-tip hardware is among the simplest and most effective life-safety measures households can take. Alongside earthquake exposure, Thurston County's flood risk at the 91th percentile nationally reinforces the value of maintaining a household emergency supply cache usable for multiple hazard scenarios. Thurston County residents should locate the main gas shutoff valve and keep an appropriate wrench nearby — gas leaks cause a significant share of earthquake-related injuries and fires, and the shutoff step is safe to take immediately after shaking stops.

Regional Context

Thurston County's composite risk score sits 24.5 points above the Washington county average, placing it among the more hazard-exposed counties in the state.

Is your household prepared for Thurston County's hazards?

Review FEMA's county-specific preparedness checklists and emergency planning guides.

FEMA Ready Guide →

Frequently Asked Questions

What is the natural disaster risk in Thurston County, WA?
Thurston County has a FEMA National Risk Index rating of Relatively High, placing it in the 94th 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.
What types of natural hazards affect Thurston County?
Thurston County is evaluated for five major natural hazard types: earthquake (99th percentile), flooding (91th percentile), wildfire (57th percentile), tornado (25th 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.
How does Thurston County risk compare to the Washington average?
Thurston County's composite risk percentile is 94th, compared to the Washington state average of 70th percentile. The state's overall risk rating is Relatively Low. This means Thurston County faces higher natural disaster risk than the typical county in Washington.
Is Thurston County at risk for earthquake?
Yes, Thurston County's earthquake risk is at the 99th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Thurston County is at the 91th percentile.
How is natural disaster risk measured?
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.
Why is Thurston County higher risk than average?
Thurston County's composite risk score of 94th percentile is above the Washington state average of 70th percentile. This elevated risk is driven by earthquake exposure (99th percentile), along with flooding and wildfire risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.

Counties with Similar Risk

Yakima County

Washington

-0.5

Relatively Moderate

94th percentile

Pacific County

Washington

-1.7

Relatively Moderate

93th percentile

Kitsap County

Washington

-2.2

Relatively Moderate

92th percentile

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

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.

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