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Washington County, Oregon

Natural disaster risk, federal disaster history and flood insurance facts.

Relatively High overall risk
3rd of 36highest risk in Oregon
$270Mexpected losses a year
15federal declarations
1 in 167homes with flood insurance
Photo: M.O. Stevens, CC BY 3.0

Washington County, Oregon has a relatively high overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 96% of US counties. It ranks 3rd of 36 counties in Oregon. The costliest hazards here are earthquakes, inland flooding and heat waves. FEMA estimates about $270 million a year in expected losses, or roughly $450 per resident. Since 1964 it has been included in 15 federal disaster or emergency declarations for natural events (10 major disasters). The most recent was in August 2024 (Lee Falls Fire). Fewer than 1 in 100 homes here carry federal flood insurance (1,044 policies). Since 1978, federal flood insurance has paid about $5.5 million on 408 claims here, including $3.0 million for floods in 1996.

FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.

Top risks in Washington County

$163 million a yearExpected losses. Damaging events about once every 70 years.
  • Ask whether an older house is bolted to its foundation.
  • Consider separate earthquake insurance where risk is high.
$80.6 million a yearExpected losses. Damaging events about once a year.
  • Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
  • Price a flood policy now. Most new federal policies take 30 days to start.
$11.2 million a yearExpected losses. Damaging events about 6 times a year.
  • Check that cooling works before summer.
  • Know where the nearest cooling center is.
HazardRatingScoreExpected loss a year
EarthquakeHigh99.0
$163M
Inland floodingHigh93.9
$81M
Heat waveHigh96.6
$11M
Cold waveHigh90.1
$9M
TornadoLow53.1
$2M
Strong windModerate80.1
$2M
Ice stormHigh91.4
$1M
LightningModerate81.7
$1M
Winter weatherModerate75.2
$216K
HailVery Low29.8
$151K
WildfireVery Low50.9
$65K
LandslideLow85.8
$43K
Volcanic activityLow89.3
$16K
AvalancheVery Low10.2
$11
DroughtVery Low12.2
$0

Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is very low and community resilience is relatively high in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

Federal declarations for natural events that included Washington County. 2020s bar runs to November 2026.

By type

Fire5
Flood4
Severe Storm4
Earthquake1
Coastal Storm1

Most recent

Aug 9, 2024Lee Falls FireFire management
Sep 15, 2020Wildfires and Straight-Line WindsMajor disaster
Sep 10, 2020Chehalem Mountain Bald Peak FireFire management
Sep 10, 2020WildfiresEmergency
Sep 8, 2020Powerline FireFire management
Feb 17, 2016Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and MudslidesMajor disaster
Mar 2, 2009Severe Winter Storm, Record and Near Record SnowMajor disaster
Dec 8, 2007Severe Storms, Flooding, Landslides, and MudslidesMajor disaster
Sep 7, 2005Hurricane Katrina EvacuationEmergency
Mar 19, 1996Severe Storms and High WindsMajor disaster
Show all 15
Feb 9, 1996High Winds, Severe Storms and FloodingMajor disaster
Apr 26, 1993EarthquakeMajor disaster
Jan 25, 1974Severe Storms, Snowmelt & FloodingMajor disaster
Jan 21, 1972Severe Storms & FloodingMajor disaster
Dec 24, 1964Heavy Rains & FloodingMajor disaster

Oregon also had 42 statewide declarations that did not name single counties.

Storm history since 1954

Tornado risk by county ›

The National Weather Service has logged 69 storm reports in Washington County since 1954, with 2 deaths and 0 injuries and about $5.7 million in reported damage. The strongest on record here was an F1 tornado on November 12, 1991.

6tornadoes
8hail reports, largest 1.75 inches
4damaging thunderstorm winds
26floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Nov 12, 1991F1–0 / 0
Oct 29, 2018EF0Forest Grove0 / 0
Jun 23, 1966F0–0 / 0
Jun 18, 2004F0Sherwood0 / 0
Oct 22, 1954F0–0 / 0

Most damaging storms

DateTypeNearDamage
Dec 7, 2015FloodDilley$2M
Dec 3, 2007FloodDilley$2M
Dec 9, 2015FloodDilley$283K
Aug 5, 2003LightningTigard$150K
Dec 18, 2015FloodDilley$141K
Jun 25, 2014Heavy RainBeaverton$140K

Source: NOAA Storm Events Database, county-based reports through Nov 20, 2024. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.

Flood insurance in Washington County

Check your address flood zone ›
0.6%of homes have federal flood insurance (1,044 policies)
38.1%of homes in mapped high-risk flood zones are insured
$5.5 millionpaid on 408 flood claims since 1978
1996costliest year, with $3 million paid

National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.

Homes in Washington County

$588,000median home value (Oregon $477,600, US $332,700)
1990median year homes were built (Oregon 1981, US 1980)
36%of homes built before 1980, before many modern wind, quake and flood building rules
1.9%of homes are mobile homes, which are the least safe in tornadoes and high winds

Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 243,278 housing units.

Compare in Oregon

All 36 ›
Largest countiesOverall riskTop hazard
Multnomah CountyHighEarthquake
Washington CountyHighEarthquake
Clackamas CountyHighEarthquake
Lane CountyHighInland flooding
Marion CountyHighEarthquake
Jackson CountyModerateInland flooding
Deschutes CountyModerateInland flooding
Linn CountyModerateEarthquake

Neighboring counties

CountyOverall riskDeclarations
Multnomah CountyHigh10
Clackamas CountyHigh21
Yamhill CountyModerate17
Columbia CountyLow14
Clatsop CountyHigh16
Tillamook CountyModerate22

Common questions about Washington County

What is the biggest natural hazard in Washington County?

Earthquake has the highest expected yearly losses in Washington County, about $163 million a year in FEMA's estimate. Inland flooding is second at $80.6 million.

How many federal disasters has Washington County had?

Washington County has been included in 15 federal disaster or emergency declarations for natural events since 1964, including 10 major disasters. The most recent was Lee Falls Fire in August 2024.

Is Washington County a high-risk place to live?

Its overall rating is Relatively High, 3rd highest of 36 in Oregon. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.

Do I need flood insurance in Washington County?

Standard home insurance does not cover flooding. About 1 in 167 homes in Washington County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.

How many tornadoes has Washington County had?

NOAA records list 6 tornadoes in Washington County since 1950. The strongest was an F1 tornado on November 12, 1991. The weather service has also logged 8 hail reports and 26 floods here.

Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.