Polk County, Oregon Natural Disaster Risk
FEMA National Risk Index assessment · OR
LowComposite Risk Score
National percentile: 73th
Polk County faces low composite natural disaster risk (NRI Risk Index score 72.8, 73th national percentile), driven primarily by earthquake and heat wave exposure. Expected annual loss across all 18 hazard types is $38M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Polk County at low composite risk, with a National Risk Index score of 72.8 out of 100 — placing it in the 73rd national percentile and below the national average for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
The county's risk is driven primarily by earthquake (ground shaking from sudden movement along geologic faults) at Medium risk — $19M in expected annual loss and about 0.02 events per year; heat wave (prolonged periods of extreme heat that threaten health and infrastructure) at Medium risk — $3M in expected annual loss and about 6.12 events per year; and volcanic activity (eruptions producing ashfall, lava, and pyroclastic hazards) at Very Low risk — $2K in expected annual loss and about 0.01 events per year. Across all hazards, FEMA estimates $38M in expected annual loss for a population of 87K.
Beyond physical exposure, Polk 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 federal record bears this out: Polk County has received 15 federal disaster declarations since 1964, including 8 for severe storm events and 4 for flood events. The most recent was Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides (severe storm), declared in April 2026.
Among 36 Oregon counties, Polk County ranks #20 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Earthquake | Medium | 0.02 / yr | $19M |
| Heat Wave | Medium | 6.12 / yr | $3M |
| Volcanic Activity | Very Low | 0.01 / yr | $2K |
| Landslide | Low | 4.22 / yr | $31K |
| Riverine Flood | Low | 0.82 / yr | $15M |
| Ice Storm | Medium | 0.60 / yr | $196K |
| Wildfire | Very Low | 0.00 / yr | $38K |
| Winter Weather | Low | 7.86 / yr | $44K |
| Lightning | Low | 4.96 / yr | $153K |
| Cold Wave | Very Low | 0.05 / yr | $187K |
| Avalanche | Very Low | 0.01 / yr | $22 |
| Tornado | Very Low | 0.06 / yr | $124K |
| Drought | Very Low | 0.32 / yr | $2 |
| Strong Wind | Very Low | 0.05 / yr | $105K |
| Hail | Very Low | 0.04 / yr | $25K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Polk County has received 15 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), Flood (4), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| April 2026 | Severe Storm | Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides |
| May 2021 | Severe Storm | Severe Winter Storm |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| February 2016 | Severe Storm | Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides |
| March 2012 | Flood | Severe Winter Storm, Flooding, Landslides, and Mudslides |
| March 2009 | Severe Storm | Severe Winter Storm, Record and Near Record Snow |
| December 2007 | Severe Storm | Severe Storms, Flooding, Landslides, and Mudslides |
| February 2007 | Severe Storm | Severe Winter Storm and Flooding |
| March 2006 | Severe Storm | Severe Storms, Flooding, Landslides, and Mudslides |
Showing the 10 most recent of 15 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Polk County?
Polk County has a composite FEMA National Risk Index score of 72.8 out of 100, placing it in the Low category and the 73th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Polk County?
The three highest-rated hazards are Earthquake (Medium, $19M EAL), Heat Wave (Medium, $3M EAL), Volcanic Activity (Very Low, $2K EAL). These account for most of the county's expected annual losses.
How does Polk County compare to other Oregon counties?
Polk County ranks #20 of 36 Oregon counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Polk County had?
FEMA records 15 federal disaster declarations for Polk County since 1964, most often 8 for severe storm events and 4 for flood 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. Polk County's $38M EAL is a statistical average, not a guarantee for any specific year or address.