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Natural hazard risk in Washington County, Oregon

Updated October 30, 2026. Based on FEMA, NOAA and OpenFEMA data. Published by Humblebee.

FEMA overall Risk Index rating: Relatively High (score 96.0 of 100)[5]

Expected annual loss (FEMA)
$270.3 million[1]
Federal disaster declarations since 1964
15[2]
NFIP flood claims paid, 1978 to 2026
$5.5 million[3]
Tornadoes recorded, 1950 to 2024
7[4]

FEMA's National Risk Index rates the overall natural hazard risk for Washington County, Oregon, Relatively High compared with other US counties, with a Risk Index score of 96.0 out of 100[5]. Within the county, the hazards with the highest FEMA scores are earthquake, heat wave and inland flooding[6].

FEMA risk ratings for each hazard

Ratings and expected losses from the FEMA National Risk Index. Each rating compares this county with all US counties for that hazard, from Very Low to Very High. They are planning estimates, not predictions, and they do not describe any single property.

FEMA's National Risk Index estimates Expected Annual Loss from all 18 natural hazards in Washington County at $270.3 million a year, rated Relatively High[1]. This is FEMA's estimate of average yearly economic loss, not money anyone paid, and FEMA says the index is not meant to predict next year's damage[7]. Earthquake accounts for the largest estimated loss at $162.9 million a year[8], followed by inland flooding at $80.6 million a year[9]. FEMA rates social vulnerability Very Low (score 12.9), a measure of how susceptible social groups are to harm from hazards[10]. FEMA rates community resilience Relatively High (score 74.3), a measure of the ability to prepare for, withstand and recover from hazards[11].

Hazards sorted by FEMA hazard-type Risk Index score, highest first
HazardFEMA risk ratingExpected annual loss
EarthquakeRelatively High$162.9 million[8]
Heat WaveRelatively High$11.2 million[12]
Inland FloodingRelatively High$80.6 million[9]
Ice StormRelatively High$1.4 million[13]
Cold WaveRelatively High$9.4 million[14]
Volcanic ActivityRelatively Low$16,000[15]
LandslideRelatively Low$43,000[16]
LightningRelatively Moderate$1.0 million[17]
Strong WindRelatively Moderate$1.7 million[18]
Winter WeatherRelatively Moderate$216,000[19]
TornadoRelatively Low$1.8 million[20]
WildfireVery Low$65,000[21]
HailVery Low$151,000[22]
DroughtVery Low$0[23]
AvalancheVery Low$11[24]

Rated Not Applicable by FEMA for this county: hurricane, tsunami[25].

Social vulnerability and community resilience

FEMA uses these two ratings to scale expected losses into the Risk Index.

FEMA measureRatingScore
Social vulnerabilityVery Low12.9[10]
Community resilienceRelatively High74.3[11]

Flooding and flood insurance

FEMA rates inland flooding risk in Washington County Relatively High compared with other US counties, with a score of 93.8[9]. OpenFEMA data show 1,044 residential flood insurance contracts in force out of 176,868 residential structures, a penetration rate of 0.6%, as of 2026-08-03[26]. A HazardFacts tally of OpenFEMA records counts 408 NFIP claims for losses from 1978 to 2026, and NFIP paid $5.5 million in total[3]. The year with the most paid claims was 1996, with 147[3].

Measure Value
Inland Flooding, FEMA risk rating[9] Relatively High, $80.6 million expected loss a year
NFIP residential flood policies in force (2026)[26] 1,044 of 176,868 homes
Homes in FEMA's mapped high-risk flood area (SFHA)[26] 1,766, of which 673 insured
NFIP flood claims, 1978 to 2026[3] 408 filed, $5.5 million paid

Is a specific address in a flood zone? Only FEMA's flood maps answer that, property by property[27]. This page describes the whole county.

Search an address on the FEMA Flood Map Service Center

Disaster declarations and tornado records

OpenFEMA lists 15 federal disaster declarations for natural hazards that include Washington County since 1964, including 5 for fire, 4 for severe storm and 4 for flood[2]. The most recent is FM-5529-OR for the Lee Falls Fire, declared 2024-08-09[28]. NOAA's Storm Prediction Center tornado database records 7 tornadoes in the county from 1950 to 2024, with the strongest rated F2 and the most recent on 2018-10-29[4].

Federal disaster declarations for natural hazards that include Washington County, since 1964
Incident type Declarations
Fire[2] 5
Severe Storm[2] 4
Flood[2] 4
Earthquake[2] 1
Coastal Storm[2] 1
Most recent declarations
Declaration Incident Declared
FM-5529-OR[28] Lee Falls Fire 2024-08-09
DR-4562-OR[28] Wildfires And Straight-Line Winds 2020-09-15
FM-5371-OR[28] Chehalem Mountain Bald Peak Fire 2020-09-10
EM-3542-OR[28] Wildfires 2020-09-10
FM-5358-OR[28] Powerline Fire 2020-09-08

How to prepare

Steps from Ready.gov, FEMA's preparedness site, for the hazards with the highest FEMA ratings here. Follow instructions from local officials and the National Weather Service when a warning is issued.

Earthquakes

Before

  • Practice Drop, Cover, and Hold On with your family and coworkers.
  • Sign up for earthquake alerts that can warn you before shaking starts.
  • Make a plan with an out-of-state contact and a place to meet if you get separated.
  • Anchor heavy items such as bookcases, refrigerators and water heaters, and keep heavy things on low shelves.
  • Consider earthquake insurance. Standard homeowners policies do not cover earthquake damage.

During

  • Drop to your hands and knees, cover your head and neck, and hold on until the shaking stops.
  • Indoors, stay where you are and avoid doorways. Outdoors, move to an open area away from buildings and power lines.
  • If you are driving, pull over, stop and set the parking brake.

Source: Ready.gov, earthquakes

Extreme heat

Before

  • Learn the signs of heat illness and how to respond.
  • Do not rely on a fan as your main way to stay cool. Fans do not lower body temperature.
  • Find cool public places, such as libraries or malls, or ask your local health department.
  • Keep heat out with window shades, weather stripping and insulation.
  • If you cannot afford cooling costs, contact LIHEAP for help.

During

  • Never leave a person or an animal in a parked car in warm weather.
  • If your home has no air conditioning, go to a cooling center.
  • Wear light, loose clothing, drink plenty of fluids and avoid hard outdoor work in the middle of the day.

Source: Ready.gov, extreme heat

Floods

Before

  • Check your flood risk with FEMA's Flood Map Service Center, and remember that floods do not follow map lines.
  • Sign up for your community's warning system. NOAA Weather Radio also broadcasts alerts.
  • Buy flood insurance through the NFIP well before a disaster. Homeowners policies do not cover flooding, and a new policy typically takes up to 30 days to go into effect.
  • Make a household plan with evacuation routes, shelter locations and what to do in a flash flood.
  • Keep important documents in a waterproof container and make password-protected digital copies.

During

  • If you are told to evacuate, leave right away and never drive around barricades.
  • Do not walk, swim or drive through floodwater. Six inches of moving water can knock you down.
  • If you are trapped in a building, go to the highest level, but do not climb into a closed attic.

Source: Ready.gov, floods

Questions people ask

Is Washington County, Oregon at risk of earthquakes?
FEMA rates earthquake risk in Washington County Relatively High compared with other US counties, with a score of 99.0 out of 100[8]. It is the hazard with the highest FEMA score in the county[6].
Is Washington County at risk of flooding?
FEMA rates inland flooding risk Relatively High compared with other US counties, with a score of 93.8 and an Expected Annual Loss of $80.6 million a year[9]. NFIP paid $5.5 million on claims for losses from 1978 to 2026[3].
Does Washington County get tornadoes?
NOAA's tornado database records 7 tornadoes in the county from 1950 to 2024, and none were rated F3/EF3 or stronger[4]. FEMA rates tornado risk Relatively Low compared with other US counties[20].
How many disasters have been declared in Washington County?
OpenFEMA lists 15 federal disaster declarations for natural hazards that include the county since 1964, 10 of them major disasters[2].
How can I check if a property is in a flood zone?
County ratings do not tell you the flood zone of a single address[27]. Look up the address on FEMA's Flood Map Service Center or ask the local floodplain manager[27].

Facts and sources

  1. FEMA National Risk Index (version 1.20, December 2025): Expected Annual Loss from all 18 natural hazards in Washington County is $270.3 million a year (Expected Annual Loss rating Relatively High, score 97.1). Of this, buildings account for $185.1 million, injuries and deaths (converted to dollars by FEMA) for... FEMA National Risk Index
  2. OpenFEMA Disaster Declarations Summaries list 15 federal disaster declarations for natural hazards that include Washington County since 1964 (10 major disaster, 5 emergency or fire management). By incident type: fire 5, severe storm 4, flood 4, earthquake 1, coastal storm 1. Biological (such as COVID-19) and other... OpenFEMA Disaster Declarations
  3. HazardFacts tally of OpenFEMA NFIP Redacted Claims (losses from 1978 to 2026): 408 National Flood Insurance Program claims were filed for losses in Washington County, 306 of them with a payment, and NFIP paid $5.5 million in total (building, contents and increased cost of compliance, in dollars of the year paid).... OpenFEMA NFIP claims
  4. NOAA Storm Prediction Center tornado database (1950 to 2024): 7 recorded tornadoes touched Washington County. The strongest were rated F2 (most recent of them on 1993-12-08). 0 were rated F3/EF3 or stronger. The most recent recorded tornado was on 2018-10-29. Ratings used the Fujita scale until early 2007 and the... NOAA Storm Prediction Center
  5. FEMA National Risk Index (version 1.20, December 2025): the overall natural hazard Risk Index rating for Washington County is Relatively High, with a Risk Index score of 96.0 out of 100. The score is the county's percentile rank among all US counties. FEMA National Risk Index
  6. Among the 18 hazards in the FEMA National Risk Index (version 1.20, December 2025), the hazards with the highest hazard-type Risk Index scores for Washington County are earthquake (99.0, Relatively High), heat wave (96.6, Relatively High), inland flooding (93.8, Relatively High). HazardFacts sorted FEMA's published... FEMA National Risk Index
  7. FEMA's National Risk Index FAQ (December 2025): Expected Annual Loss is FEMA's estimate of the average economic loss in dollars from natural hazards each year. The index is not meant to predict how much damage a community will have in the next year, and a hazard can still cause damage where a rating is low. Scores... FEMA National Risk Index documentation
  8. FEMA National Risk Index (version 1.20, December 2025), earthquake in Washington County: Risk Index rating Relatively High (score 99.0 of 100). Expected Annual Loss $162.9 million a year (rating Relatively High). FEMA's modeled annual frequency is 0.0147 events per year. FEMA National Risk Index
  9. FEMA National Risk Index (version 1.20, December 2025), inland flooding in Washington County: Risk Index rating Relatively High (score 93.8 of 100). Expected Annual Loss $80.6 million a year (rating Relatively High). Annualized frequency 0.75 event-days per year, from recorded occurrences over a period of record of... FEMA National Risk Index
  10. FEMA National Risk Index (version 1.20, December 2025): Social Vulnerability rating for Washington County is Very Low (score 12.9). FEMA describes social vulnerability as how susceptible social groups are to the harm natural hazards cause. FEMA National Risk Index
  11. FEMA National Risk Index (version 1.20, December 2025): Community Resilience rating for Washington County is Relatively High (score 74.3). FEMA describes community resilience as a community's ability to prepare for, withstand and recover from hazards. FEMA National Risk Index
  12. FEMA National Risk Index (version 1.20, December 2025), heat wave in Washington County: Risk Index rating Relatively High (score 96.6 of 100). Expected Annual Loss $11.2 million a year (rating Relatively High). Annualized frequency 6.25 event-days per year, from recorded occurrences over a period of record of 18... FEMA National Risk Index
  13. FEMA National Risk Index (version 1.20, December 2025), ice storm in Washington County: Risk Index rating Relatively High (score 91.4 of 100). Expected Annual Loss $1.4 million a year (rating Relatively High). Annualized frequency 1.22 event-days per year, from recorded occurrences over a period of record of 68 years. FEMA National Risk Index
  14. FEMA National Risk Index (version 1.20, December 2025), cold wave in Washington County: Risk Index rating Relatively High (score 90.1 of 100). Expected Annual Loss $9.4 million a year (rating Relatively High). Annualized frequency 0.23 event-days per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  15. FEMA National Risk Index (version 1.20, December 2025), volcanic activity in Washington County: Risk Index rating Relatively Low (score 89.2 of 100). Expected Annual Loss $16,000 a year (rating Relatively Low). FEMA National Risk Index
  16. FEMA National Risk Index (version 1.20, December 2025), landslide in Washington County: Risk Index rating Relatively Low (score 85.8 of 100). Expected Annual Loss $43,000 a year (rating Relatively Low). FEMA National Risk Index
  17. FEMA National Risk Index (version 1.20, December 2025), lightning in Washington County: Risk Index rating Relatively Moderate (score 81.7 of 100). Expected Annual Loss $1.0 million a year (rating Relatively High). Annualized frequency 5.88 events per year, from recorded occurrences over a period of record of 24 years. FEMA National Risk Index
  18. FEMA National Risk Index (version 1.20, December 2025), strong wind in Washington County: Risk Index rating Relatively Moderate (score 80.0 of 100). Expected Annual Loss $1.7 million a year (rating Relatively High). Annualized frequency 0.05 events per year, from recorded occurrences over a period of record of 38... FEMA National Risk Index
  19. FEMA National Risk Index (version 1.20, December 2025), winter weather in Washington County: Risk Index rating Relatively Moderate (score 75.2 of 100). Expected Annual Loss $216,000 a year (rating Relatively Moderate). Annualized frequency 10.65 events per year, from recorded occurrences over a period of record of... FEMA National Risk Index
  20. FEMA National Risk Index (version 1.20, December 2025), tornado in Washington County: Risk Index rating Relatively Low (score 53.1 of 100). Expected Annual Loss $1.8 million a year (rating Relatively Low). Annualized frequency 0.07 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  21. FEMA National Risk Index (version 1.20, December 2025), wildfire in Washington County: Risk Index rating Very Low (score 50.8 of 100). Expected Annual Loss $65,000 a year (rating Very Low). FEMA's modeled annual frequency is 0 events per year. FEMA National Risk Index
  22. FEMA National Risk Index (version 1.20, December 2025), hail in Washington County: Risk Index rating Very Low (score 29.7 of 100). Expected Annual Loss $151,000 a year (rating Relatively Low). Annualized frequency 0.05 events per year, from recorded occurrences over a period of record of 37 years. FEMA National Risk Index
  23. FEMA National Risk Index (version 1.20, December 2025), drought in Washington County: Risk Index rating Very Low (score 12.2 of 100). Expected Annual Loss $0 a year (rating Very Low). Annualized frequency 0.19 event-days per year, from recorded occurrences over a period of record of 22 years. FEMA National Risk Index
  24. FEMA National Risk Index (version 1.20, December 2025), avalanche in Washington County: Risk Index rating Very Low (score 10.2 of 100). Expected Annual Loss $11 a year (rating Very Low). Annualized frequency 0.01 events per year, from recorded occurrences over a period of record of 28 years. FEMA National Risk Index
  25. FEMA National Risk Index (version 1.20, December 2025) rates these hazards Not Applicable for Washington County: hurricane, tsunami. FEMA uses Not Applicable when its source data has no historical record of the hazard in the community and the hazard is not considered geographically possible there. FEMA National Risk Index documentation
  26. NFIP Residential Penetration Rates (OpenFEMA, as of 2026-08-03): 1,044 residential flood insurance contracts were in force in Washington County, out of 176,868 residential structures, a penetration rate of 0.6%. Inside FEMA's mapped Special Flood Hazard Area there were 1,766 residential structures and 673... OpenFEMA NFIP penetration rates
  27. FEMA's Flood Map Service Center is the official public source for flood maps (Flood Insurance Rate Maps) produced under the National Flood Insurance Program. Flood zones apply to specific properties: look up an address there or ask the local floodplain manager. County-level ratings do not tell you the flood zone of... FEMA Flood Map Service Center
  28. Most recent federal disaster declarations for natural hazards (table on this page). OpenFEMA Disaster Declarations

FEMA's National Risk Index compares each county with all other US counties. Ratings are relative (Very Low to Very High), not a measure of safety. Never call a place safe, unsafe, good or bad to live in. Risk Index and Expected Annual Loss values are FEMA estimates for planning. They do not predict next year's losses and do not apply to a single property. Flood zones are set by FEMA flood maps for specific properties. County ratings and flood insurance counts do not tell anyone whether an address is in a flood zone. Disaster declaration, NFIP and tornado counts are records of the past for this county only. Do not compare with other counties unless a fact does.

Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties, v1.20 (December 2025). Retrieved from fema.maps.arcgis.com on October 30, 2026. This product uses the Federal Emergency Management Agency's National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s). This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.