Jefferson County Disaster Risk

Jefferson County has a FEMA National Risk Index rating of Very Low, placing it in the 40th percentile nationally out of 3,144 counties. This composite score reflects the county's overall exposure to natural hazards including floods, wildfires, tornadoes, earthquakes, and hurricanes, weighted by expected annual loss and social vulnerability.

Jefferson County is evaluated for five major natural hazard types: earthquake (81th percentile), wildfire (63th percentile), flooding (37th percentile), tornado (7th percentile). The highest-risk hazard is earthquake at the 81th percentile nationally. These scores are derived from FEMA's National Risk Index, which analyzes expected annual loss, social vulnerability, and community resilience for each hazard type.

Jefferson County's composite risk percentile is 40th, compared to the Idaho state average of 39th percentile. The state's overall risk rating is Very Low. This means Jefferson County faces higher natural disaster risk than the typical county in Idaho.

Yes, Jefferson County's earthquake risk is at the 81th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Jefferson County is at the 37th percentile.

FEMA's National Risk Index (NRI) calculates risk scores for 18 natural hazard types across all U.S. counties and census tracts. The composite score combines Expected Annual Loss (estimated dollar losses from each hazard), Social Vulnerability (demographic factors affecting disaster impact), and Community Resilience (ability to recover). Percentile scores rank each county against all 3,144 U.S. counties, and risk ratings range from Very Low to Very High.

Jefferson County's composite risk score of 40th percentile is above the Idaho state average of 39th percentile. This elevated risk is driven by earthquake exposure (81th percentile), along with wildfire risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.