Ada County Disaster Risk
Ada County, Idaho
FEMA Risk Rating
Relatively Moderate
National Percentile
88th
of 3,144 counties
State Rank
#1
of 44 (1 = highest risk)
Flood Risk
90th
percentile
Hazard Risk Breakdown
Flood
River, coastal, and surface flooding risk
Moderate
Higher than 90% of US counties
Wildfire
Wildland and wildland-urban interface fire risk
Relatively High
Higher than 98% of US counties
Tornado
Tornado and severe thunderstorm risk
Very Low
Higher than 27% of US counties
Earthquake
Seismic activity and ground shaking risk
Moderate
Higher than 88% of US counties
Risk Overview
About Natural Disaster Risk in Ada County, Idaho
Ada County faces well above-average disaster risk
With a composite risk score of 87.75, Ada County ranks in the relatively moderate category—significantly higher than the national average of 50. This elevated score reflects the county's exposure to multiple hazard types, particularly wildfire and earthquake risks that far exceed typical American counties.
The riskiest county in Idaho by far
Ada County's composite risk score of 87.75 towers above Idaho's state average of 38.51, making it the most disaster-prone county in the state. This 2.3x multiplier over the state baseline reflects Ada's unique geography and its role as Idaho's urban and economic hub.
Ada far exceeds risk in surrounding counties
Ada County's score of 87.75 dwarfs neighboring Boise County (48.92) and Adams County (39.57), which sit near or below the state average. The dramatic difference underscores Ada's distinct exposure profile compared to its more rural neighbors.
Wildfires and earthquakes dominate your risk
Ada County faces a wildfire risk score of 98.25 and an earthquake risk of 88.23—both among the highest in the nation. Floods also pose serious concern with a risk score of 89.82, making multi-hazard preparedness essential for Ada County residents and businesses.
Comprehensive coverage is critical for Ada
Standard homeowners insurance typically excludes wildfire and earthquake damage—coverage gaps that can be financially devastating in Ada County. Residents should urgently explore wildfire, earthquake, and flood insurance options, and ensure emergency preparedness plans address all three major hazards.
Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor
Preparedness Guide
What to Prepare for in Ada County
Top Hazards by Exposure
Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)
Risk Advisory: Ada County
Risk Verdict
Natural hazard risk in Ada County is higher than the majority of U.S. counties, with a national composite rank of 88th. Ada County's elevated composite score reflects cumulative multi-hazard exposure; households should prepare for the county's two or three primary hazard types.
Hazard Breakdown
Wildfire risk is Ada County's dominant natural hazard, ranked at the 98th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 90th percentile nationally. Additional tracked hazards include earthquake (88th percentile), tornado (27th percentile).
Preparedness Context
At the 98th percentile nationally for wildfire, Ada County residents should verify whether their insurance policy includes replacement cost coverage for structures and whether the insurer still writes new policies in this fire-risk zone. A secondary flood exposure at the 90th percentile nationally means Ada County residents face hazards from two distinct natural peril categories during different seasons. Local USFS or Cal Fire (where applicable) fire risk maps and seasonal Red Flag Warning alerts from the National Weather Service are two free resources Ada County residents can use to stay ahead of rapidly changing wildfire conditions.
Regional Context
A composite score 49.2 points above the Idaho state average puts Ada County in a higher-risk category than most counties in the state.
Is your household prepared for Ada County's hazards?
Review FEMA's county-specific preparedness checklists and emergency planning guides.
Frequently Asked Questions
What is the natural disaster risk in Ada County, ID?
What types of natural hazards affect Ada County?
How does Ada County risk compare to the Idaho average?
Is Ada County at risk for wildfire?
How is natural disaster risk measured?
Why is Ada County higher risk than average?
Data Source
Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.
Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.