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

Bonneville County Disaster Risk

Bonneville County, Idaho

FEMA Risk Rating

Relatively Moderate

National Percentile

82th

of 3,144 counties

State Rank

#2

of 44 (1 = highest risk)

Flood Risk

79th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Relatively Low

Higher than 79% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Moderate

Higher than 90% of US counties

Tornado

Tornado and severe thunderstorm risk

Very Low

Higher than 16% of US counties

Earthquake

Seismic activity and ground shaking risk

Moderate

Higher than 94% of US counties

Risk Overview

About Natural Disaster Risk in Bonneville County, Idaho

Bonneville ranks moderately risky nationally

Bonneville County scores 82.41, placing it in the relatively moderate risk category compared to national averages. This score reflects particularly high wildfire and earthquake exposure, with significant flood risk as well.

Idaho's second-highest composite risk

At 82.41, Bonneville is among Idaho's highest-risk counties, more than double the state average of 38.51. The county's proximity to the Teton Range and its geologic setting create outsized earthquake hazards.

Significantly riskier than surrounding areas

Bonneville's 82.41 score far exceeds Butte County's 4.42 and Caribou County's 7.22, reflecting its exposure to major earthquake faults and active fire zones. Madison and Teton counties face similar seismic and wildfire pressures.

Earthquakes and wildfires dominate exposure

Earthquake risk scores 94.18—the highest in the state—while wildfire risk reaches 90.33, making these the defining hazards for Bonneville residents. Flood risk of 78.59 adds a third significant concern, particularly in river-adjacent areas.

Earthquake and wildfire insurance essential

Bonneville's extreme earthquake score of 94.18 makes earthquake coverage critical; many insurers offer it as an add-on to homeowners policies. Wildfire and flood coverage are equally urgent given your county's 90.33 wildfire and 78.59 flood scores.

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

Preparedness Guide

What to Prepare for in Bonneville County

Top Hazards by Exposure

  1. #1
    EarthquakePrepare
    94th percentile
  2. #2
    WildfirePrepare
    90th percentile
  3. #3
    FloodPrepare
    79th percentile

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

Risk Advisory: Bonneville County

Risk Verdict

FEMA's National Risk Index rates Bonneville County at the 82th percentile nationally — above average and worth proactive preparation. Residents should prioritize a formal household emergency plan, including evacuation routes, insurance review, and a well-stocked emergency kit.

Hazard Breakdown

Earthquake risk is Bonneville County's dominant natural hazard, ranked at the 94th percentile nationally under FEMA's National Risk Index. Wildfire ranks second at the 90th percentile nationally. Additional tracked hazards include flood (79th percentile), tornado (16th percentile).

Preparedness Context

Earthquake exposure at the 94th percentile nationally puts Bonneville County in a zone where utilities — gas, water, electrical — are the most common post-quake hazard. Knowing how to shut off the main gas valve is an important household skill to develop before an event occurs. Wildfire at the 90th percentile nationally is a separate hazard dimension for Bonneville County that requires different protective strategies from earthquake preparedness. Bonneville County households benefit from keeping shoes and a flashlight near the bed — post-earthquake navigation through debris in the dark is a common cause of secondary injury. This low-cost step has outsized protective value.

Regional Context

Bonneville County is 43.9 composite risk points above the Idaho average, indicating that residents face greater natural hazard exposure than most of their in-state neighbors.

Is your household prepared for Bonneville 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 Bonneville County, ID?
Bonneville County has a FEMA National Risk Index rating of Relatively Moderate, placing it in the 82th 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 Bonneville County?
Bonneville County is evaluated for five major natural hazard types: earthquake (94th percentile), wildfire (90th percentile), flooding (79th percentile), tornado (16th percentile). The highest-risk hazard is earthquake at the 94th 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 Bonneville County risk compare to the Idaho average?
Bonneville County's composite risk percentile is 82th, compared to the Idaho state average of 39th percentile. The state's overall risk rating is Very Low. This means Bonneville County faces higher natural disaster risk than the typical county in Idaho.
Is Bonneville County at risk for earthquake?
Yes, Bonneville County's earthquake risk is at the 94th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Bonneville County is at the 79th 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 Bonneville County higher risk than average?
Bonneville County's composite risk score of 82th percentile is above the Idaho state average of 39th percentile. This elevated risk is driven by earthquake exposure (94th percentile), along with wildfire and flooding risk. 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.