Cassia County, ID
FEMA National Risk Index scores, disaster declarations & hazard data
Cassia County has experienced 5 federally declared disasters since 1965, most recently Covid-19 in 2020. Its overall natural hazard risk is rated Relatively Low — lower risk than most US counties.
Cassia County's highest-rated hazards are wildfire, winter weather, and earthquake, with its top risk rated "Relatively Moderate" by FEMA's National Risk Index.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Cassia County has been designated in 5 declarations since 1965, covering 3 disaster types including biological (2), flood (2), hurricane (1).
| Year | Type | Event name |
|---|---|---|
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2017 | Flood | Severe Winter Storms And Flooding |
| 2005 | Hurricane | Hurricane Katrina |
| 1965 | Flood | Heavy Rains & Flooding |
Source: FEMA OpenFEMA Disaster Declarations Summaries. A single disaster can produce more than one record per county. Data current through September 2026.
Risk by hazard type
| Hazard | Risk rating | Risk score | Recorded events | Deaths | Prop. damage |
|---|---|---|---|---|---|
| Wildfire | Relatively Moderate | 94.7 | 0 | 0 | — |
| Inland Flooding | Relatively Low | 52.7 | 8 | 0 | $5.4M |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Relatively Low | 74.5 | — | — | — |
| Heat Wave | Relatively Low | 56.6 | 0 | 0 | — |
| Tornado | Very Low | 9.8 | 2 | 0 | — |
| Hurricane | Not Applicable | — | 0 | 0 | — |
| Hail | Very Low | 10.9 | 7 | 0 | — |
| Strong Wind | Relatively Low | 23.2 | 0 | 0 | — |
| Winter Weather | Relatively Moderate | 81.9 | 0 | 0 | — |
| Ice Storm | Very Low | 13.8 | — | — | — |
| Cold Wave | Relatively Low | 42.7 | — | — | — |
| Lightning | Relatively Moderate | 69.1 | 0 | 0 | — |
| Drought | Very Low | 25.2 | 0 | 0 | — |
| Landslide | Very Low | 49.5 | 0 | 0 | — |
| Avalanche | Very Low | 56.9 | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic Activity | Very Low | 47.2 | — | — | — |
Scores are 0–100 percentiles relative to all US counties — higher means more exposed, not that a disaster is likely this year. Event counts: NOAA Storm Events 2016–2026; earthquake counts from USGS ComCat (M3.0+, 1996–2026). See the methodology page for details.
Community vulnerability
Cassia County ranks in the 56th percentile (Moderate) for community vulnerability — a measure of how hard disaster impacts tend to hit residents. Higher vulnerability means more displacement, worse health outcomes, and slower recovery after a disaster.
| SVI theme | Percentile | Vulnerability level |
|---|---|---|
| Overall | 56th | Moderate |
| Socioeconomic status | 51st | Moderate |
| Household characteristics | 54th | Moderate |
| Racial & ethnic minority status | 70th | Moderate |
| Housing type & transportation | 52nd | Moderate |
Source: CDC/ATSDR Social Vulnerability Index 2022. Percentiles compare counties nationally — higher means more vulnerable relative to other counties. See CDC SVI for full methodology.
Future risk outlook
| Wildfire metric | National percentile | Level |
|---|---|---|
| Burn probability | 98th | Very High |
| Risk to homes | 99th | Very High |
| Buildings in direct exposure zone | 43.6% | — |
Wildfire: USDA Forest Service Wildfire Risk to Communities (RDS-2020-0016-2) — modeled values, not annual forecasts. See wildfirerisk.org. Inland flood and heat projections pending data availability; coastal sea-level projections are available for select coastal counties below — see the data page.
Nearby counties
Frequently asked questions
What natural hazards pose the greatest risk in Cassia County?
According to the FEMA National Risk Index, the highest-risk hazards in Cassia County, Idaho are wildfire, winter weather, and earthquake. The county's overall natural hazard risk is rated Relatively Low — lower risk than most US counties.
Has Cassia County received federal disaster declarations?
Yes. Cassia County has received 5 federal disaster declarations since 1965, including declarations in 2020. The most common disaster type on record is biological (2 declarations).
Has Cassia County had any FEMA disaster declarations in 2024, 2025, or 2026?
No federal disaster declarations have been recorded for Cassia County since the start of 2024. Its most recent declaration on record is Covid-19 in 2020.
How does Cassia County's natural hazard risk compare to nearby counties?
Among neighboring counties, Box Elder County, UT has the highest overall natural hazard risk (Relatively Low) and Lincoln County, ID has the lowest (Very Low). Cassia County is rated Relatively Low overall.
How is Cassia County's composite disaster risk index calculated?
Cassia County's composite disaster risk index — officially FEMA's National Risk Index (NRI) — scores every US county on a 0–100 percentile scale across 18 natural hazard types, factoring in expected annual loss, social vulnerability, and community resilience. Cassia County's composite score of 44 means its overall natural hazard risk is higher than 44% of US counties.