Multnomah County, Oregon: Natural Disaster Risk and History
Multnomah County, Oregon has a Relatively High natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 98.5 out of 100, higher than about 98% of US counties, with earthquakes, landslides and heat waves scoring highest of its 18 hazards and $440 million a year in expected losses.
OpenFEMA lists 10 federal disaster declarations that included Multnomah County since 1964, not counting 2 for COVID-19; the latest is DR-4768-OR (Severe Winter Storms, Straight-Line Winds, Landslides, and Mudslides, declared 13 April 2024). NOAA's Storm Prediction Center recorded 5 tornadoes touching Multnomah County from 1950 to 2025.
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Population 814,167 Buildings worth $183 billion Area 470 sq mi Risk rank in Oregon 1 of 36 FIPS 41051
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 | 99.6 | $326 million | about once every 47 years | — |
| Landslide | Relatively Moderate | 96.9 | $295,655 | about 2.1 a year | — |
| Heat wave | Relatively High | 96.8 | $10.0 million | about 6.3 a year | 98 |
| Inland flooding | Relatively High | 95.5 | $91 million | about once every 2.5 years | 11 |
| Volcanic activity | Relatively Moderate | 93.5 | $159,024 | about once every 84 years | 7 |
| Ice storm | Relatively High | 91.8 | $1.2 million | about 1.6 a year | 109 |
| Cold wave | Relatively High | 91.0 | $8.5 million | about once every 3.1 years | 6.1 |
| Winter weather | Relatively High | 85.2 | $308,577 | about 16 a year | 302 |
| Wildfire | Relatively Low | 67.3 | $154,683 | rarer than once in 1,000 years | — |
| Strong wind | Relatively Moderate | 65.5 | $924,901 | about once every 15 years | 3 |
| Tornado | Relatively Low | 47.4 | $1.2 million | about once every 26 years | 6 |
| Lightning | Relatively Low | 45.8 | $219,448 | about 8 a year | 153,262 strikes |
| Coastal flooding | Relatively Low | 43.4 | $42,828 | about once every 3.5 years | — |
| Avalanche | Very Low | 18.4 | $31 | about once every 100 years | 0 |
| Drought | Very Low | 12.5 | $4 | about 1.9 a year | 112 |
| Hail | Very Low | 1.9 | $2,904 | about once every 13 years | 2.9 |
| 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 10
Most common: Severe Storm 4, Flood 3, Fire 2, Coastal Storm 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 1960s | 1 | Flood |
| 1970s | 1 | Flood |
| 1990s | 1 | Flood |
| 2000s | 3 | Severe Storm ×2, Coastal Storm |
| 2010s | 2 | Fire, Severe Storm |
| 2020s | 2 | Severe Storm, Fire |
The last 10
Widest declarations that included Multnomah County
- Hurricane Katrina Evacuation (2005, EM-3228-OR): 36 Oregon counties designated.
- Heavy Rains & Flooding (1964, DR-184-OR): 36 Oregon counties designated.
- Severe Winter Storms (2004, DR-1510-OR): 30 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 5
| Tornadoes touching the county | 5 |
|---|---|
| Strongest-rated | (E)F1 ×1 |
| Peak month | April (1) |
| Deadliest | — |
| Longest path | 1 Jul 2019, EF0, 1.6 mi path |
| Most recent | 8 Sep 2019, 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 | 4 | 1 | 0 | 0 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 0 | 0 | 0 | 0 | 2 | 0 | 3 | 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 Multnomah County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Multnomah County (this page) | — | Relatively High | 98.5 | Earthquake |
| Clark County, WA | 26 km | Relatively Moderate | 92.2 | Earthquake |
| Clackamas County | 43 km | Relatively High | 94.9 | Earthquake |
| Washington County | 53 km | Relatively High | 96.0 | Earthquake |
| Hood River County | 60 km | Very Low | 32.1 | Volcanic activity |
| Skamania County, WA | 66 km | Relatively Low | 49.7 | Volcanic activity |
Nearest by distance between county centres. Every county in Oregon, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively Low 29.8 |
|---|---|
| Community resilience | Very High 95.5 |
| Community risk factor | 0.96 |
| Expected annual loss, all hazards | $440 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 Multnomah 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
- Landslide: Landslides recorded
- Heat wave: Heatstroke warning signs
- 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 Multnomah County
What natural disasters is Multnomah County, Oregon most at risk from?
Multnomah County, Oregon has a Relatively High natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 98.5 out of 100, higher than about 98% of US counties, with earthquakes, landslides and heat waves scoring highest of its 18 hazards and $440 million a year in expected losses.
How many federal disaster declarations has Multnomah County had?
OpenFEMA lists 10 federal disaster declarations that included Multnomah County since 1964, not counting 2 for COVID-19; the latest is DR-4768-OR (Severe Winter Storms, Straight-Line Winds, Landslides, and Mudslides, declared 13 April 2024). Another 33 Oregon declarations were made statewide without a county list.
How many tornadoes have hit Multnomah County?
NOAA's Storm Prediction Center recorded 5 tornadoes touching Multnomah 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.