riskbycounty
FEMA NRI 1.19.0Updated Nov 2023 · Coverage 2014–2023Methodology

Boise County Disaster Risk

Boise County, Idaho

FEMA Risk Rating

Relatively Low

National Percentile

49th

of 3,144 counties

State Rank

#15

of 44 (1 = highest risk)

Flood Risk

43th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Relatively Low

Higher than 43% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Relatively High

Higher than 97% of US counties

Tornado

Tornado and severe thunderstorm risk

Very Low

Higher than 4% of US counties

Earthquake

Seismic activity and ground shaking risk

Very Low

Higher than 40% of US counties

Risk Overview

About Natural Disaster Risk in Boise County, Idaho

Boise County faces moderate disaster risk

Boise County's composite risk score of 48.92 sits just below the national average of 50, earning a 'relatively low' rating. While the county faces meaningful exposure to wildfire and moderate flood risks, its overall hazard profile is slightly more favorable than the typical American county.

Near-average risk for Idaho

Boise County's score of 48.92 slightly exceeds Idaho's state average of 38.51, placing it just above the midpoint of statewide risk. This near-average position reflects balanced exposure across multiple hazard categories without extreme concentrations in any single threat.

Boise safer than Ada, less risky than Blaine

Boise County's 48.92 score sits well below Ada County's 87.75 and modestly below Blaine County's 65.36, positioning it as the safer central Idaho option. Its risk level is comparable to or slightly above most other rural Idaho counties.

Wildfire is your dominant natural hazard

Boise County faces an exceptional wildfire risk of 97.23, among the highest in Idaho and ranking as the county's primary threat by far. Flood risk (42.94) and earthquake risk (40.04) are moderate and below state averages, while tornado risk is minimal.

Wildfire insurance is your top priority

Given Boise County's 97.23 wildfire risk score, securing dedicated wildfire insurance should be your immediate action. While earthquake and flood risks are lower, reviewing coverage options for these hazards remains prudent, and maintaining defensible space around your home is essential.

Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor

Preparedness Guide

What to Prepare for in Boise County

Top Hazards by Exposure

  1. #1
    WildfirePrepare
    97th percentile
  2. #2
    FloodPrepare
    43th percentile
  3. #3
    EarthquakePrepare
    40th percentile

Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)

Risk Advisory: Boise County

Risk Verdict

Boise County sits below the national average for natural disaster exposure, ranking at the 49th percentile across all U.S. counties. A preparedness foundation — alert registration, household communication plan, and a basic supply review — costs little and remains valuable even at Boise County's favorable 49th percentile ranking.

Hazard Breakdown

Wildfire risk is Boise County's dominant natural hazard, ranked at the 97th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 43th percentile nationally. Additional tracked hazards include earthquake (40th percentile), tornado (4th percentile).

Preparedness Context

At the 97th percentile nationally for wildfire, Boise 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. The county's flood exposure at the 43th percentile nationally complements the wildfire risk — saturating rain after burn scarring often triggers secondary flood and debris flow events. 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 Boise County residents can use to stay ahead of rapidly changing wildfire conditions.

Regional Context

A composite score 10.4 points above the Idaho state average puts Boise County in a higher-risk category than most counties in the state.

Is your household prepared for Boise County's hazards?

Review FEMA's county-specific preparedness checklists and emergency planning guides.

FEMA Ready Guide →

Frequently Asked Questions

What is the natural disaster risk in Boise County, ID?
Boise County has a FEMA National Risk Index rating of Relatively Low, placing it in the 49th 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.
What types of natural hazards affect Boise County?
Boise County is evaluated for five major natural hazard types: wildfire (97th percentile), flooding (43th percentile), earthquake (40th percentile), tornado (4th percentile). The highest-risk hazard is wildfire at the 97th 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.
How does Boise County risk compare to the Idaho average?
Boise County's composite risk percentile is 49th, compared to the Idaho state average of 39th percentile. The state's overall risk rating is Very Low. This means Boise County faces higher natural disaster risk than the typical county in Idaho.
Is Boise County at risk for wildfire?
Yes, Boise County's wildfire risk is at the 97th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Boise County is at the 43th percentile.
How is natural disaster risk measured?
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.
Why is Boise County higher risk than average?
Boise County's composite risk score of 49th percentile is above the Idaho state average of 39th percentile. This elevated risk is driven by wildfire exposure (97th percentile). Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.
By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

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.