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

Twin Falls County Disaster Risk

Twin Falls County, Idaho

FEMA Risk Rating

Relatively Low

National Percentile

47th

of 3,144 counties

State Rank

#16

of 44 (1 = highest risk)

Flood Risk

51th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Relatively Low

Higher than 51% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Moderate

Higher than 94% of US counties

Tornado

Tornado and severe thunderstorm risk

Very Low

Higher than 13% of US counties

Earthquake

Seismic activity and ground shaking risk

Relatively Low

Higher than 74% of US counties

Risk Overview

About Natural Disaster Risk in Twin Falls County, Idaho

Twin Falls County has relatively low disaster risk

With a composite risk score of 46.95, Twin Falls County sits below the national average and ranks as relatively low-risk for natural disasters. This places the county in a safer zone compared to most U.S. counties, though still above several Idaho peers.

Mid-range risk among Idaho counties

Twin Falls County scores 46.95 against Idaho's state average of 38.51, placing it in the middle tier of the state's 44 counties. While not the safest, it faces lower combined disaster risk than many other Idaho communities.

Riskier than Teton and Washington counties

Twin Falls County (46.95) faces noticeably higher disaster risk than neighboring Teton County (29.45) and Washington County (30.31). Valley County presents a comparable threat profile at 55.63, making Twin Falls relatively positioned between safer and higher-risk neighbors.

Wildfires and earthquakes lead threats

Wildfire risk dominates Twin Falls County's hazard profile at 93.96, while earthquake exposure stands at 73.95—both substantially above many U.S. counties. Flood risk (51.11) adds a secondary concern, though tornadoes remain minimal at 13.42.

Bundle wildfire and earthquake insurance

Twin Falls County residents should add wildfire and earthquake coverage to standard homeowners policies, which exclude both hazards. These two risks account for most of your county's natural disaster exposure and warrant dedicated protection.

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

Preparedness Guide

What to Prepare for in Twin Falls County

Top Hazards by Exposure

  1. #1
    WildfirePrepare
    94th percentile
  2. #2
    EarthquakePrepare
    74th percentile
  3. #3
    FloodPrepare
    51th percentile

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

Risk Advisory: Twin Falls County

Risk Verdict

Twin Falls County's FEMA risk score places it at the 47th percentile nationally, indicating lower-than-typical exposure for a U.S. county. Residents of Twin Falls County can use the 47th percentile ranking as a baseline, while recognizing that individual properties may still lie in specific hazard zones that differ from the county average.

Hazard Breakdown

Wildfire risk is Twin Falls County's dominant natural hazard, ranked at the 94th percentile nationally under FEMA's National Risk Index. Earthquake ranks second at the 74th percentile nationally. Additional tracked hazards include flood (51th percentile), tornado (13th percentile).

Preparedness Context

Twin Falls County sits at the 94th percentile for wildfire exposure. Signing up for Twin Falls County's county emergency alert system and knowing the pre-planned evacuation route before conditions deteriorate are the two highest-value preparedness actions for residents here. Alongside wildfire, earthquake at the 74th percentile nationally means a multi-season preparedness mindset — fire season and flood or storm season often require different household plans. In Twin Falls County, wildfire smoke often precedes the flame front by hours or days; households benefit from tracking EPA's AirNow.gov and having HEPA air filtration available as a first line of indoor protection when air quality alerts are issued.

Regional Context

The Idaho county average is 8.4 composite points below Twin Falls County's score, a gap that reflects the county's elevated position in the state's hazard distribution.

Is your household prepared for Twin Falls 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 Twin Falls County, ID?
Twin Falls County has a FEMA National Risk Index rating of Relatively Low, placing it in the 47th 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 Twin Falls County?
Twin Falls County is evaluated for five major natural hazard types: wildfire (94th percentile), earthquake (74th percentile), flooding (51th percentile), tornado (13th percentile). The highest-risk hazard is wildfire 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 Twin Falls County risk compare to the Idaho average?
Twin Falls County's composite risk percentile is 47th, compared to the Idaho state average of 39th percentile. The state's overall risk rating is Very Low. This means Twin Falls County faces higher natural disaster risk than the typical county in Idaho.
Is Twin Falls County at risk for wildfire?
Yes, Twin Falls County's wildfire risk is at the 94th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Twin Falls County is at the 51th 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 Twin Falls County higher risk than average?
Twin Falls County's composite risk score of 47th percentile is above the Idaho state average of 39th percentile. This elevated risk is driven by wildfire exposure (94th percentile), along with earthquake 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.