Boundary County, Idaho Natural Disaster Risk
FEMA National Risk Index assessment · ID
Very LowComposite Risk Score
National percentile: 26th
Boundary County faces very low composite natural disaster risk (NRI Risk Index score 26.1, 26th national percentile), driven primarily by landslide and avalanche exposure. Expected annual loss across all 18 hazard types is $7M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Boundary County at very low composite risk, with a National Risk Index score of 26.1 out of 100 — placing it in the 26th 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 landslide (downhill movement of rock, soil, and debris on unstable slopes) at Medium risk — $369K in expected annual loss and about 0.67 events per year; avalanche (fast-moving snow and debris sliding down steep mountain slopes) at Medium risk — $487K in expected annual loss and about 0.10 events per year; and wildfire (uncontrolled fires that spread across wildland and into communities) at Low risk — $340K in expected annual loss and about 0.00 events per year. Across all hazards, FEMA estimates $7M in expected annual loss for a population of 12K.
Beyond physical exposure, Boundary 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.
History supports the rating: Boundary County has received 12 federal disaster declarations since 1967, including 4 for severe storm events and 2 for biological events. The most recent was Straight-Line Winds (straight-line winds), declared in April 2026.
Among 44 Idaho counties, Boundary County ranks #29 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | Medium | 0.67 / yr | $369K |
| Avalanche | Medium | 0.10 / yr | $487K |
| Wildfire | Low | 0.00 / yr | $340K |
| Winter Weather | Medium | 27.10 / yr | $96K |
| Cold Wave | Low | 1.42 / yr | $684K |
| Riverine Flood | Low | 0.50 / yr | $5M |
| Heat Wave | Very Low | 2.79 / yr | $112K |
| Earthquake | Very Low | 0.00 / yr | $36K |
| Lightning | Very Low | 20.60 / yr | $48K |
| Drought | Very Low | 22.29 / yr | $520 |
| Strong Wind | Very Low | 0.12 / yr | $28K |
| Hail | Very Low | 0.13 / yr | $6K |
| Tornado | Very Low | 0.01 / yr | $8K |
| Ice Storm | Very Low | 0.01 / yr | $336 |
| 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
Boundary County has received 12 federal disaster declarations since 1967, most recently Straight-Line Winds in April 2026. Most frequent causes: Severe Storm (4), Biological (2), Flood (2).
| Declared | Type | Disaster |
|---|---|---|
| April 2026 | Straight-Line Winds | Straight-Line Winds |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| May 2017 | Flood | Severe Storms, Flooding, Landslides, and Mudslides |
| December 2015 | Severe Storm | Severe Storm and Straight-Line Wind |
| September 2005 | Hurricane | Hurricane Katrina |
| June 1997 | Severe Storm | Severe Storms, Snowmelt, Land/Mud Slides, Flooding |
| January 1997 | Severe Storm | Severe Storms, Flooding, Mud and Landslides |
| February 1996 | Severe Storm | Severe Storms and Flooding |
| May 1980 | Volcanic Eruption | Volcanic Eruption, Mt. St. Helens |
Showing the 10 most recent of 12 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Boundary County?
Boundary County has a composite FEMA National Risk Index score of 26.1 out of 100, placing it in the Very Low category and the 26th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Boundary County?
The three highest-rated hazards are Landslide (Medium, $369K EAL), Avalanche (Medium, $487K EAL), Wildfire (Low, $340K EAL). These account for most of the county's expected annual losses.
How does Boundary County compare to other Idaho counties?
Boundary County ranks #29 of 44 Idaho counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Boundary County had?
FEMA records 12 federal disaster declarations for Boundary County since 1967, most often 4 for severe storm events and 2 for biological events. The most recent was Straight-Line Winds, 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. Boundary County's $7M EAL is a statistical average, not a guarantee for any specific year or address.