Boise County
Idaho — Natural Disaster Risk Assessment
LowComposite Risk Score
National percentile: 49th
Boise County faces low composite natural disaster risk (NRI Risk Index score 48.9, 49th national percentile), driven primarily by landslide and wildfire exposure. Expected annual loss across all 18 hazard types is $16M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Landslide | Medium | 2.09 / yr | $356K |
| Wildfire | Medium | 0.02 / yr | $8M |
| Avalanche | High | 0.10 / yr | $1M |
| Winter Weather | Low | 17.70 / yr | $70K |
| Riverine Flood | Low | 0.82 / yr | $6M |
| Earthquake | Very Low | 0.01 / yr | $158K |
| Volcanic Activity | Very Low | 0.00 / yr | $3 |
| Strong Wind | Low | 0.29 / yr | $225K |
| Heat Wave | Very Low | 1.47 / yr | $36K |
| Ice Storm | Very Low | 0.04 / yr | $8K |
| Drought | Very Low | 7.80 / yr | $1 |
| Lightning | Very Low | 23.22 / yr | $32K |
| Cold Wave | Very Low | 0.05 / yr | $13K |
| Hail | Very Low | 0.20 / yr | $11K |
| Tornado | Very Low | 0.08 / yr | $13K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Frequently Asked Questions
What is the overall natural disaster risk for Boise County?
Boise County has a composite FEMA National Risk Index score of 48.9 out of 100, placing it in the Low category and the 49th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Boise County?
The three highest-rated hazards are Landslide (Medium, $356K EAL), Wildfire (Medium, $8M EAL), Avalanche (High, $1M EAL). These account for most of the county's expected annual losses.
How does Boise County compare to other Idaho counties?
Boise County ranks #15 of 44 Idaho counties for overall natural disaster risk, with a low rating.
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. Boise County's $16M EAL is a statistical average, not a guarantee for any specific year or address.