Union County, Oregon Natural Disaster Risk
FEMA National Risk Index assessment · OR
LowComposite Risk Score
National percentile: 44th
Union County faces low composite natural disaster risk (NRI Risk Index score 43.5, 44th national percentile), driven primarily by wildfire and cold wave exposure. Expected annual loss across all 18 hazard types is $12M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Union County carries a low composite natural disaster risk, with a National Risk Index score of 43.5 out of 100 — placing it in the 44th 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.
Most of Union County's expected losses come from wildfire (uncontrolled fires that spread across wildland and into communities) at Medium risk — $2M in expected annual loss and about 0.01 events per year; cold wave (prolonged spells of dangerously low temperatures) at Medium risk — $4M in expected annual loss and about 0.18 events per year; and avalanche (fast-moving snow and debris sliding down steep mountain slopes) at Medium risk — $656K in expected annual loss and about 0.07 events per year. Across all hazards, FEMA estimates $12M in expected annual loss for a population of 26K.
Beyond physical exposure, Union County has a medium social vulnerability rating (how susceptible the population is to harm) and a low community resilience rating (its capacity to prepare for and recover from disasters). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
The federal record bears this out: Union County has received 9 federal disaster declarations since 1964, including 3 for flood events and 2 for severe storm events. The most recent was Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides (severe storm), declared in April 2026.
Among 36 Oregon counties, Union County ranks #24 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Wildfire | Medium | 0.01 / yr | $2M |
| Cold Wave | Medium | 0.18 / yr | $4M |
| Avalanche | Medium | 0.07 / yr | $656K |
| Winter Weather | Medium | 18.67 / yr | $192K |
| Earthquake | Low | 0.00 / yr | $1M |
| Landslide | Low | 0.89 / yr | $4K |
| Ice Storm | Low | 0.04 / yr | $76K |
| Heat Wave | Low | 2.53 / yr | $276K |
| Riverine Flood | Low | 0.39 / yr | $4M |
| Lightning | Low | 19.46 / yr | $99K |
| Hail | Very Low | 0.38 / yr | $69K |
| Strong Wind | Very Low | 0.19 / yr | $124K |
| Drought | Very Low | 22.43 / yr | $909 |
| Tornado | Very Low | 0.06 / yr | $25K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Union County has received 9 federal disaster declarations since 1964, most recently Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides in April 2026. Most frequent causes: Flood (3), Severe Storm (2), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| April 2026 | Severe Storm | Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides |
| April 2020 | Flood | Severe Storms, Flooding, Landslides, and Mudslides |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2005 | Coastal Storm | Hurricane Katrina Evacuation |
| February 2004 | Severe Storm | Severe Winter Storms |
| February 1996 | Flood | High Winds, Severe Storms and Flooding |
| April 1977 | Drought | Drought |
| December 1964 | Flood | Heavy Rains & Flooding |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Union County?
Union County has a composite FEMA National Risk Index score of 43.5 out of 100, placing it in the Low category and the 44th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Union County?
The three highest-rated hazards are Wildfire (Medium, $2M EAL), Cold Wave (Medium, $4M EAL), Avalanche (Medium, $656K EAL). These account for most of the county's expected annual losses.
How does Union County compare to other Oregon counties?
Union County ranks #24 of 36 Oregon counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Union County had?
FEMA records 9 federal disaster declarations for Union County since 1964, most often 3 for flood events and 2 for severe storm 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. Union County's $12M EAL is a statistical average, not a guarantee for any specific year or address.