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

Cassia County Disaster Risk

Cassia County, Idaho

FEMA Risk Rating

Relatively Low

National Percentile

44th

of 3,144 counties

State Rank

#19

of 44 (1 = highest risk)

Flood Risk

53th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Relatively Low

Higher than 53% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Relatively High

Higher than 95% of US counties

Tornado

Tornado and severe thunderstorm risk

Very Low

Higher than 10% 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 Cassia County, Idaho

Cassia ranks moderately low nationally

Cassia County scores 43.58, placing it slightly above the national average with relatively low overall risk. The score reflects elevated wildfire and earthquake exposure, offset by lower flood and tornado threats.

Above-average risk for Idaho

At 43.58, Cassia exceeds Idaho's state average of 38.51, ranking it in the middle-to-upper tier of state counties. The score reflects this southeastern county's position along major fire corridors.

Riskier than neighboring Twin Falls

Cassia's 43.58 score exceeds many neighboring southeastern Idaho counties, driven largely by its 94.69 wildfire score—the highest in the state. Caribou (7.22) to the north faces far less overall exposure.

Wildfires and earthquakes dominate Cassia

Wildfire risk scores an exceptional 94.69—the highest in all of Idaho—while earthquake exposure reaches 74.46, making these the defining hazards. Flood risk of 52.74 is moderate; tornado risk is minimal at 9.83.

Wildfire coverage is absolutely critical

Cassia's 94.69 wildfire score is the state's highest, making standalone wildfire insurance non-negotiable for all homeowners here. Add earthquake coverage to comprehensive protection, as your 74.46 earthquake score also demands dedicated policy language.

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

Preparedness Guide

What to Prepare for in Cassia County

Top Hazards by Exposure

  1. #1
    WildfirePrepare
    95th percentile
  2. #2
    EarthquakePrepare
    74th percentile
  3. #3
    FloodPrepare
    53th percentile

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

Risk Advisory: Cassia County

Risk Verdict

With a national percentile rank of 44th, Cassia County faces below-average hazard exposure relative to U.S. counties as a whole. The 44th percentile national ranking is one lens; Cassia County residents also benefit from reviewing which specific hazard types drive the county's composite score and preparing accordingly.

Hazard Breakdown

Wildfire risk is Cassia County's dominant natural hazard, ranked at the 95th percentile nationally under FEMA's National Risk Index. Earthquake ranks second at the 74th percentile nationally. Additional tracked hazards include flood (53th percentile), tornado (10th percentile).

Preparedness Context

At the 95th percentile nationally for wildfire risk, Cassia County households benefit from creating defensible space — a buffer of reduced vegetation around structures — and reviewing whether homeowners insurance covers wildfire damage in this region. A secondary earthquake exposure at the 74th percentile nationally means Cassia County residents face hazards from two distinct natural peril categories during different seasons. Enrolling in the county's wireless emergency alert system and keeping a vehicle at least half-full during peak fire season are low-cost habits that dramatically reduce evacuation lag time for Cassia County residents.

Regional Context

At 5.1 points above the Idaho state average, Cassia County carries meaningfully higher natural disaster exposure than a typical Idaho county.

Is your household prepared for Cassia 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 Cassia County, ID?
Cassia County has a FEMA National Risk Index rating of Relatively Low, placing it in the 44th 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 Cassia County?
Cassia County is evaluated for five major natural hazard types: wildfire (95th percentile), earthquake (74th percentile), flooding (53th percentile), tornado (10th percentile). The highest-risk hazard is wildfire at the 95th 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 Cassia County risk compare to the Idaho average?
Cassia County's composite risk percentile is 44th, compared to the Idaho state average of 39th percentile. The state's overall risk rating is Very Low. This means Cassia County faces higher natural disaster risk than the typical county in Idaho.
Is Cassia County at risk for wildfire?
Yes, Cassia County's wildfire risk is at the 95th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Cassia County is at the 53th 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 Cassia County higher risk than average?
Cassia County's composite risk score of 44th percentile is above the Idaho state average of 39th percentile. This elevated risk is driven by wildfire exposure (95th 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.