Adams County, Idaho Natural Disaster Risk
FEMA National Risk Index assessment · ID
Very LowComposite Risk Score
National percentile: 40th
Adams County faces very low composite natural disaster risk (NRI Risk Index score 39.6, 40th national percentile), driven primarily by wildfire and landslide exposure. Expected annual loss across all 18 hazard types is $10M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Adams County at very low composite risk, with a National Risk Index score of 39.6 out of 100 — placing it in the 40th national percentile and among the lowest-risk counties in the country. 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 — $5M 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 — $58K in expected annual loss and about 1.11 events per year; and avalanche (fast-moving snow and debris sliding down steep mountain slopes) at High risk — $913K in expected annual loss and about 0.07 events per year. Across all hazards, FEMA estimates $10M in expected annual loss for a population of 4K.
Beyond physical exposure, Adams County has a 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: Adams County has received 9 federal disaster declarations since 1974, including 2 for biological events and 2 for flood events. The most recent was Four Corners Fire (fire), declared in August 2022.
Among 44 Idaho counties, Adams County ranks #22 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Wildfire | Medium | 0.02 / yr | $5M |
| Landslide | Medium | 1.11 / yr | $58K |
| Avalanche | High | 0.07 / yr | $913K |
| Winter Weather | Low | 19.64 / yr | $39K |
| Earthquake | Very Low | 0.00 / yr | $106K |
| Riverine Flood | Low | 0.29 / yr | $3M |
| Heat Wave | Very Low | 1.69 / yr | $43K |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
| Drought | Very Low | 17.89 / yr | $50 |
| Lightning | Very Low | 22.44 / yr | $26K |
| Cold Wave | Very Low | 0.05 / yr | $18K |
| Hail | Very Low | 0.16 / yr | $7K |
| Tornado | Very Low | 0.04 / yr | $5K |
| Strong Wind | Very Low | 0.14 / yr | $11K |
| Ice Storm | Very Low | 0.01 / yr | $860 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Adams County has received 9 federal disaster declarations since 1974, most recently Four Corners Fire in August 2022. Most frequent causes: Biological (2), Flood (2), Severe Storm (2).
| Declared | Type | Disaster |
|---|---|---|
| August 2022 | Fire | Four Corners Fire |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| June 2019 | Flood | Severe Storms, Flooding, Landslides, and Mudslides |
| July 2010 | Severe Storm | Severe Storms and Flooding |
| September 2005 | Hurricane | Hurricane Katrina |
| January 1997 | Severe Storm | Severe Storms, Flooding, Mud and Landslides |
| May 1977 | Drought | Drought |
| January 1974 | Flood | Severe Storms, Snowmelt & Flooding |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Adams County?
Adams County has a composite FEMA National Risk Index score of 39.6 out of 100, placing it in the Very Low category and the 40th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Adams County?
The three highest-rated hazards are Wildfire (Medium, $5M EAL), Landslide (Medium, $58K EAL), Avalanche (High, $913K EAL). These account for most of the county's expected annual losses.
How does Adams County compare to other Idaho counties?
Adams County ranks #22 of 44 Idaho counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Adams County had?
FEMA records 9 federal disaster declarations for Adams County since 1974, most often 2 for biological events and 2 for flood events. The most recent was Four Corners Fire, declared in August 2022.
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. Adams County's $10M EAL is a statistical average, not a guarantee for any specific year or address.