Clackamas County, Oregon Natural Disaster Risk
FEMA National Risk Index assessment · OR
HighComposite Risk Score
National percentile: 95th
Clackamas County faces high composite natural disaster risk (NRI Risk Index score 94.9, 95th national percentile), driven primarily by earthquake and landslide exposure. Expected annual loss across all 18 hazard types is $219M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Clackamas County at high composite risk, with a National Risk Index score of 94.9 out of 100 — placing it in the 95th national percentile and in the upper tier of natural-disaster risk nationally. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Most of Clackamas County's expected losses come from earthquake (ground shaking from sudden movement along geologic faults) at High risk — $109M in expected annual loss and about 0.02 events per year; landslide (downhill movement of rock, soil, and debris on unstable slopes) at Medium risk — $210K in expected annual loss and about 1.93 events per year; and volcanic activity (eruptions producing ashfall, lava, and pyroclastic hazards) at Medium risk — $495K in expected annual loss and about 0.01 events per year. Across all hazards, FEMA estimates $219M in expected annual loss for a population of 421K.
Beyond physical exposure, Clackamas County has a very low social vulnerability rating (how susceptible the population is to harm) and a high community resilience rating (its capacity to prepare for and recover from disasters). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
The county's disaster history tells the same story: Clackamas County has received 23 federal disaster declarations since 1964, including 8 for severe storm events and 7 for fire events. The most recent was Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides (severe storm), declared in April 2026.
Among 36 Oregon counties, Clackamas County ranks #6 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Earthquake | High | 0.02 / yr | $109M |
| Landslide | Medium | 1.93 / yr | $210K |
| Volcanic Activity | Medium | 0.01 / yr | $495K |
| Heat Wave | Medium | 4.92 / yr | $8M |
| Cold Wave | High | 0.38 / yr | $15M |
| Riverine Flood | High | 0.93 / yr | $77M |
| Strong Wind | High | 0.08 / yr | $3M |
| Ice Storm | High | 1.11 / yr | $1M |
| Wildfire | Low | 0.00 / yr | $1M |
| Avalanche | High | 0.13 / yr | $2M |
| Winter Weather | High | 26.07 / yr | $368K |
| Lightning | High | 8.43 / yr | $1M |
| Tornado | Low | 0.15 / yr | $1M |
| Hail | Very Low | 0.13 / yr | $165K |
| Coastal Flood | Very Low | 0.31 / yr | $200 |
| Drought | Very Low | 6.80 / yr | $378 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Clackamas County has received 23 federal disaster declarations since 1964, most recently Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides in April 2026. Most frequent causes: Severe Storm (8), Fire (7), Flood (4).
| Declared | Type | Disaster |
|---|---|---|
| April 2026 | Severe Storm | Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides |
| April 2024 | Severe Storm | Severe Winter Storms, Straight-Line Winds, Landslides, and Mudslides |
| September 2022 | Fire | Milo Mciver Fire |
| May 2021 | Severe Storm | Severe Winter Storm |
| September 2020 | Fire | Wildfires and Straight-Line Winds |
| September 2020 | Fire | Wildfires |
| September 2020 | Fire | Clakamas County Fire Complex |
| September 2020 | Fire | Riverside Fire |
| September 2020 | Fire | Beachie Creek Lionshead Fire Complex |
| March 2020 | Biological | Covid-19 Pandemic |
Showing the 10 most recent of 23 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Clackamas County?
Clackamas County has a composite FEMA National Risk Index score of 94.9 out of 100, placing it in the High category and the 95th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Clackamas County?
The three highest-rated hazards are Earthquake (High, $109M EAL), Landslide (Medium, $210K EAL), Volcanic Activity (Medium, $495K EAL). These account for most of the county's expected annual losses.
How does Clackamas County compare to other Oregon counties?
Clackamas County ranks #6 of 36 Oregon counties for overall natural disaster risk, with a high rating.
How many federally declared disasters has Clackamas County had?
FEMA records 23 federal disaster declarations for Clackamas County since 1964, most often 8 for severe storm events and 7 for fire events. The most recent was Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides, declared in April 2026.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Clackamas County's $219M EAL is a statistical average, not a guarantee for any specific year or address.