Jefferson County
Idaho — Natural Disaster Risk Assessment
Very LowComposite Risk Score
National percentile: 40th
Jefferson County faces very low composite natural disaster risk (NRI Risk Index score 40.1, 40th national percentile), driven primarily by winter weather and cold wave exposure. Expected annual loss across all 18 hazard types is $17M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Winter Weather | Medium | 13.69 / yr | $329K |
| Cold Wave | Medium | 2.56 / yr | $6M |
| Earthquake | Low | 0.01 / yr | $2M |
| Heat Wave | Medium | 1.94 / yr | $2M |
| Wildfire | Very Low | 0.00 / yr | $138K |
| Volcanic Activity | Very Low | 0.00 / yr | $37 |
| Lightning | Low | 30.94 / yr | $381K |
| Riverine Flood | Low | 0.39 / yr | $6M |
| Landslide | Very Low | 0.22 / yr | $596 |
| Drought | Very Low | 58.68 / yr | $9K |
| Hail | Very Low | 0.36 / yr | $100K |
| Strong Wind | Very Low | 0.90 / yr | $133K |
| Ice Storm | Very Low | 0.01 / yr | $8K |
| Tornado | Very Low | 0.12 / yr | $47K |
| Avalanche | Very Low | 0.01 / yr | $0 |
| 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 Jefferson County?
Jefferson County has a composite FEMA National Risk Index score of 40.1 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 Jefferson County?
The three highest-rated hazards are Winter Weather (Medium, $329K EAL), Cold Wave (Medium, $6M EAL), Earthquake (Low, $2M EAL). These account for most of the county's expected annual losses.
How does Jefferson County compare to other Idaho counties?
Jefferson County ranks #21 of 44 Idaho counties for overall natural disaster risk, with a very 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. Jefferson County's $17M EAL is a statistical average, not a guarantee for any specific year or address.