Franklin County, Idaho Natural Disaster Risk
FEMA National Risk Index assessment · ID
Very LowComposite Risk Score
National percentile: 8th
Franklin County faces very low composite natural disaster risk (NRI Risk Index score 7.6, 8th national percentile), driven primarily by wildfire and earthquake exposure. Expected annual loss across all 18 hazard types is $5M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Franklin County carries a very low composite natural disaster risk, with a National Risk Index score of 7.6 out of 100 — placing it in the 8th 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.
The county's risk is driven primarily by wildfire (uncontrolled fires that spread across wildland and into communities) at Low risk — $487K in expected annual loss and about 0.01 events per year; earthquake (ground shaking from sudden movement along geologic faults) at Low risk — $1M in expected annual loss and about 0.01 events per year; and winter weather (heavy snow, blizzards, and hazardous winter conditions) at Medium risk — $142K in expected annual loss and about 20.64 events per year. Across all hazards, FEMA estimates $5M in expected annual loss for a population of 14K.
Beyond physical exposure, Franklin County has a very low social vulnerability rating (how susceptible the population is to harm) and a low community resilience rating (its capacity to prepare for and recover from disasters). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
The federal record bears this out: Franklin County has received 4 federal disaster declarations since 2005, including 2 for biological events and 1 for flood events. The most recent was Covid-19 Pandemic (biological), declared in April 2020.
Among 44 Idaho counties, Franklin County ranks #37 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Wildfire | Low | 0.01 / yr | $487K |
| Earthquake | Low | 0.01 / yr | $1M |
| Winter Weather | Medium | 20.64 / yr | $142K |
| Landslide | Very Low | 0.91 / yr | $978 |
| Lightning | Low | 34.30 / yr | $211K |
| Heat Wave | Very Low | 1.46 / yr | $147K |
| Avalanche | Very Low | 0.01 / yr | $90 |
| Volcanic Activity | Very Low | 0.00 / yr | $1 |
| Cold Wave | Very Low | 0.50 / yr | $316K |
| Riverine Flood | Very Low | 0.25 / yr | $3M |
| Drought | Very Low | 74.13 / yr | $2K |
| Strong Wind | Very Low | 0.58 / yr | $104K |
| Hail | Very Low | 0.34 / yr | $23K |
| Ice Storm | Very Low | 0.01 / yr | $3K |
| Tornado | Very Low | 0.05 / yr | $11K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Franklin County has received 4 federal disaster declarations since 2005, most recently Covid-19 Pandemic in April 2020. Most frequent causes: Biological (2), Flood (1), Hurricane (1).
| Declared | Type | Disaster |
|---|---|---|
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| April 2017 | Flood | Severe Winter Storms and Flooding |
| September 2005 | Hurricane | Hurricane Katrina |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Franklin County?
Franklin County has a composite FEMA National Risk Index score of 7.6 out of 100, placing it in the Very Low category and the 8th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Franklin County?
The three highest-rated hazards are Wildfire (Low, $487K EAL), Earthquake (Low, $1M EAL), Winter Weather (Medium, $142K EAL). These account for most of the county's expected annual losses.
How does Franklin County compare to other Idaho counties?
Franklin County ranks #37 of 44 Idaho counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Franklin County had?
FEMA records 4 federal disaster declarations for Franklin County since 2005, most often 2 for biological events and 1 for flood events. The most recent was Covid-19 Pandemic, declared in April 2020.
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. Franklin County's $5M EAL is a statistical average, not a guarantee for any specific year or address.