Ada County Disaster Risk

Ada County has a FEMA National Risk Index rating of Relatively Moderate, placing it in the 88th 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.

Ada County is evaluated for five major natural hazard types: wildfire (98th percentile), flooding (90th percentile), earthquake (88th percentile), tornado (27th percentile). The highest-risk hazard is wildfire at the 98th 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.

Ada County's composite risk percentile is 88th, compared to the Idaho state average of 39th percentile. The state's overall risk rating is Very Low. This means Ada County faces higher natural disaster risk than the typical county in Idaho.

Yes, Ada County's wildfire risk is at the 98th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Ada County is at the 90th 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.

Ada County's composite risk score of 88th percentile is above the Idaho state average of 39th percentile. This elevated risk is driven by wildfire exposure (98th percentile), along with flooding and earthquake risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.