Cassia County
Idaho — Natural Disaster Risk Assessment
LowComposite Risk Score
National percentile: 44th
Cassia County faces low composite natural disaster risk (NRI Risk Index score 43.6, 44th national percentile), driven primarily by wildfire and winter weather 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
| Wildfire | Medium | 0.01 / yr | $4M |
| Winter Weather | Medium | 15.31 / yr | $259K |
| Earthquake | Low | 0.01 / yr | $1M |
| Lightning | Medium | 28.38 / yr | $547K |
| Avalanche | Very Low | 0.01 / yr | $1K |
| Heat Wave | Low | 2.49 / yr | $572K |
| Riverine Flood | Low | 0.75 / yr | $8M |
| Landslide | Very Low | 0.85 / yr | $1K |
| Volcanic Activity | Very Low | 0.00 / yr | $12 |
| Cold Wave | Low | 0.39 / yr | $823K |
| Drought | Very Low | 64.26 / yr | $15K |
| Strong Wind | Low | 0.51 / yr | $244K |
| Ice Storm | Very Low | 0.01 / yr | $9K |
| Hail | Very Low | 0.30 / yr | $40K |
| Tornado | Very Low | 0.22 / yr | $70K |
| 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 Cassia County?
Cassia County has a composite FEMA National Risk Index score of 43.6 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 Cassia County?
The three highest-rated hazards are Wildfire (Medium, $4M EAL), Winter Weather (Medium, $259K EAL), Earthquake (Low, $1M EAL). These account for most of the county's expected annual losses.
How does Cassia County compare to other Idaho counties?
Cassia County ranks #19 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. Cassia County's $16M EAL is a statistical average, not a guarantee for any specific year or address.