Owyhee County, Idaho Natural Disaster Risk
FEMA National Risk Index assessment · ID
LowComposite Risk Score
National percentile: 44th
Owyhee County faces low composite natural disaster risk (NRI Risk Index score 44.1, 44th national percentile), driven primarily by wildfire and avalanche exposure. Expected annual loss across all 18 hazard types is $8M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Owyhee County is low, with a National Risk Index score of 44.1 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.
Risk here concentrates in wildfire (uncontrolled fires that spread across wildland and into communities) at Medium risk — $3M in expected annual loss and about 0.02 events per year; avalanche (fast-moving snow and debris sliding down steep mountain slopes) at Low risk — $4K in expected annual loss and about 0.01 events per year; and landslide (downhill movement of rock, soil, and debris on unstable slopes) at Low risk — $4K in expected annual loss and about 1.57 events per year. Across all hazards, FEMA estimates $8M in expected annual loss for a population of 12K.
Beyond physical exposure, Owyhee County has a very high social vulnerability rating (how susceptible the population is to harm) and a very low community resilience rating (its capacity to prepare for and recover from disasters). That combination — a more vulnerable population with limited resilience — can amplify the human cost of any given event.
The county's disaster history tells the same story: Owyhee County has received 6 federal disaster declarations since 1964, including 2 for biological events and 2 for severe storm events. The most recent was Covid-19 Pandemic (biological), declared in April 2020.
Among 44 Idaho counties, Owyhee County ranks #18 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Wildfire | Medium | 0.02 / yr | $3M |
| Avalanche | Low | 0.01 / yr | $4K |
| Landslide | Low | 1.57 / yr | $4K |
| Winter Weather | Medium | 12.24 / yr | $83K |
| Riverine Flood | Low | 0.89 / yr | $5M |
| Heat Wave | Low | 2.88 / yr | $208K |
| Volcanic Activity | Very Low | 0.00 / yr | $5 |
| Earthquake | Very Low | 0.00 / yr | $65K |
| Ice Storm | Very Low | 0.05 / yr | $10K |
| Drought | Very Low | 94.18 / yr | $2K |
| Lightning | Very Low | 22.57 / yr | $37K |
| Hail | Very Low | 0.14 / yr | $31K |
| Strong Wind | Very Low | 0.19 / yr | $49K |
| Cold Wave | Very Low | 0.12 / yr | $44K |
| Tornado | Very Low | 0.28 / yr | $17K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Owyhee County has received 6 federal disaster declarations since 1964, most recently Covid-19 Pandemic in April 2020. Most frequent causes: Biological (2), Severe Storm (2), Hurricane (1).
| Declared | Type | Disaster |
|---|---|---|
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| February 2006 | Severe Storm | Severe Storms and Flooding |
| September 2005 | Hurricane | Hurricane Katrina |
| January 1997 | Severe Storm | Severe Storms, Flooding, Mud and Landslides |
| December 1964 | Flood | Heavy Rains & Flooding |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Owyhee County?
Owyhee County has a composite FEMA National Risk Index score of 44.1 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 Owyhee County?
The three highest-rated hazards are Wildfire (Medium, $3M EAL), Avalanche (Low, $4K EAL), Landslide (Low, $4K EAL). These account for most of the county's expected annual losses.
How does Owyhee County compare to other Idaho counties?
Owyhee County ranks #18 of 44 Idaho counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Owyhee County had?
FEMA records 6 federal disaster declarations for Owyhee County since 1964, most often 2 for biological events and 2 for severe storm events. The most recent was Covid-19 Pandemic, declared in April 2020.
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. Owyhee County's $8M EAL is a statistical average, not a guarantee for any specific year or address.