Washington County, Oregon: Natural Disaster Risk and History
Washington County, Oregon has a Relatively High natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 96.0 out of 100, higher than about 96% of US counties, with earthquakes, heat waves and inland (river and flash) flooding scoring highest of its 18 hazards and $270 million a year in expected losses.
OpenFEMA lists 15 federal disaster declarations that included Washington County since 1964, not counting 2 for COVID-19; the latest is FM-5529-OR (Lee Falls Fire, declared 9 August 2024). NOAA's Storm Prediction Center recorded 7 tornadoes touching Washington County from 1950 to 2025.
Live weather alerts for Oregon All official warnings Latest FEMA declarations
Population 600,172 Buildings worth $132 billion Area 734 sq mi Risk rank in Oregon 3 of 36 FIPS 41067
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Earthquake | Relatively High | 99.0 | $163 million | about once every 68 years | — |
| Heat wave | Relatively High | 96.6 | $11 million | about 6.3 a year | 98 |
| Inland flooding | Relatively High | 93.9 | $81 million | about once every 1.3 years | 21 |
| Ice storm | Relatively High | 91.4 | $1.4 million | about 1.2 a year | 82 |
| Cold wave | Relatively High | 90.1 | $9.4 million | about once every 4.4 years | 4.3 |
| Volcanic activity | Relatively Low | 89.3 | $15,778 | about once every 88 years | 4 |
| Landslide | Relatively Low | 85.8 | $43,274 | about 3.9 a year | — |
| Lightning | Relatively Moderate | 81.7 | $1.0 million | about 5.9 a year | 58,186 strikes |
| Strong wind | Relatively Moderate | 80.1 | $1.7 million | about once every 18 years | 3 |
| Winter weather | Relatively Moderate | 75.2 | $216,465 | about 11 a year | 202 |
| Tornado | Relatively Low | 53.1 | $1.8 million | about once every 14 years | 4 |
| Wildfire | Very Low | 50.9 | $64,957 | rarer than once in 1,000 years | — |
| Hail | Very Low | 29.8 | $151,124 | about once every 19 years | 2 |
| Drought | Very Low | 12.2 | — | about once every 5.2 years | 14 |
| Avalanche | Very Low | 10.2 | $11 | about once every 100 years | 0 |
| Coastal flooding | No Rating | 0.0 | — | — | — |
| Hurricane | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
Score: FEMA's percentile among US counties that face the hazard (higher = more risk). Expected loss: FEMA's modelled average yearly loss to buildings, people (as a statistical value) and crops. How often: FEMA's annualised frequency of the hazard in the county; for some hazards it counts event-days, so it is a rough guide, not a forecast. "Not Applicable" means FEMA does not model that hazard here.
Federal disaster declarations 15
Most common: Fire 5, Severe Storm 4, Flood 4, Coastal Storm 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 1960s | 1 | Flood |
| 1970s | 2 | Flood ×2 |
| 1990s | 3 | Severe Storm, Flood, Earthquake |
| 2000s | 3 | Severe Storm ×2, Coastal Storm |
| 2010s | 1 | Severe Storm |
| 2020s | 5 | Fire ×5 |
The last 10
Widest declarations that included Washington County
- Hurricane Katrina Evacuation (2005, EM-3228-OR): 36 Oregon counties designated.
- Heavy Rains & Flooding (1964, DR-184-OR): 36 Oregon counties designated.
- High Winds, Severe Storms and Flooding (1996, DR-1099-OR): 27 Oregon counties designated.
Named storms in its declarations: Hurricane Katrina (2005).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Oregon also had 33 statewide declarations with no county list.
Tornado record since 1950 7
| Tornadoes touching the county | 7 |
|---|---|
| Strongest-rated | (E)F2 ×1 |
| Peak month | October (3) |
| Deadliest | — |
| Longest path | 8 Dec 1993, F2, 6 mi path |
| Most recent | 29 Oct 2018, EF0, 0.1 mi path |
| Deaths / injuries on those paths | 0 / 0 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 5 | 1 | 1 | 0 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 1 | 2 | 0 | 0 | 2 | 1 | 1 | 0 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How Washington County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Washington County (this page) | — | Relatively High | 96.0 | Earthquake |
| Yamhill County | 40 km | Relatively Moderate | 82.9 | Earthquake |
| Columbia County | 43 km | Relatively Low | 70.7 | Earthquake |
| Tillamook County | 49 km | Relatively Moderate | 81.3 | Earthquake |
| Multnomah County | 53 km | Relatively High | 98.5 | Earthquake |
| Clark County, WA | 54 km | Relatively Moderate | 92.2 | Earthquake |
Nearest by distance between county centres. Every county in Oregon, ranked.
Vulnerability and resilience
| Social vulnerability | Very Low 12.9 |
|---|---|
| Community resilience | Relatively High 74.3 |
| Community risk factor | 0.81 |
| Expected annual loss, all hazards | $270 million |
FEMA scales expected losses up where social vulnerability is high (people who may find it harder to prepare, evacuate or recover) and down where community resilience is high. A factor above 1 raises the risk score. For social vulnerability a high rating is worse; for resilience a high rating is better.
Prepare for Washington County's main hazards
- Right now: National Weather Service alerts for Oregon · all official warnings on Global Incident Tracker.
- Earthquake: Earthquakes today · Earthquake safety guide
- Heat wave: Heatstroke warning signs
- Inland flooding: Flood safety: why shallow water kills · Floods recorded
- Your property's flood zone: FEMA Flood Map Service Center ↗ — this page cannot tell you that.
- Official preparedness guidance: Ready.gov ↗ and your county emergency management office.
What this page shows, and what it misses
FEMA's National Risk Index rates a whole county against every other US county; it is a planning-level estimate for nationwide comparison, not a flood-zone map and not a substitute for a local risk assessment or the risk to one home. Declarations are presidential disaster, emergency and fire management declarations that named this county; state declarations and SBA or USDA designations are not included. Tornadoes are counted when the county is one of up to four listed on the track; 670 tornadoes that crossed a state line carry no county list in NOAA's file and are left out.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. 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).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. This product uses the Federal Emergency Management Agency's OpenFEMA API, 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).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about Washington County
What natural disasters is Washington County, Oregon most at risk from?
Washington County, Oregon has a Relatively High natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 96.0 out of 100, higher than about 96% of US counties, with earthquakes, heat waves and inland (river and flash) flooding scoring highest of its 18 hazards and $270 million a year in expected losses.
How many federal disaster declarations has Washington County had?
OpenFEMA lists 15 federal disaster declarations that included Washington County since 1964, not counting 2 for COVID-19; the latest is FM-5529-OR (Lee Falls Fire, declared 9 August 2024). Another 33 Oregon declarations were made statewide without a county list.
How many tornadoes have hit Washington County?
NOAA's Storm Prediction Center recorded 7 tornadoes touching Washington County from 1950 to 2025.
Is the National Risk Index a flood zone map?
No. The National Risk Index is a planning-level estimate for a whole county, built for nationwide comparison. It does not tell you the flood zone or the risk of a single property: for that, look up the address on FEMA's Flood Map Service Center (msc.fema.gov) and ask your local floodplain manager.