Big Horn County, WY
FEMA National Risk Index scores, disaster declarations & hazard data
Big Horn County has experienced 4 federally declared disasters since 1978, most recently Covid-19 in 2020. Its overall natural hazard risk is rated Very Low — among the lowest-risk counties in the country.
Big Horn County's highest-rated hazards are landslide, wildfire, and earthquake, with its top risk rated "Relatively High" by FEMA's National Risk Index. NOAA records 21 storm events in the county over the past decade.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Big Horn County has been designated in 4 declarations since 1978, covering 3 disaster types including biological (2), severe storm (1), flood (1).
| Year | Type | Event name |
|---|---|---|
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2011 | Severe Storm | Severe Storms, Flooding, And Landslides |
| 1978 | Flood | Severe Storms, Flooding & Mudslides |
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 | Very Low | 61.4 | 0 | 0 | — |
| Inland Flooding | Relatively Low | 52.4 | 7 | 0 | $10K |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Relatively Low | 61.4 | 1 | — | — |
| Heat Wave | Very Low | 8.8 | 6 | 0 | — |
| Tornado | Very Low | 16.7 | 1 | 0 | — |
| Hurricane | Not Applicable | — | 0 | 0 | — |
| Hail | Very Low | 26.6 | 8 | 0 | — |
| Strong Wind | Very Low | 12 | 0 | 0 | — |
| Winter Weather | Relatively Low | 45.9 | 0 | 0 | — |
| Ice Storm | Very Low | 8.9 | — | — | — |
| Cold Wave | Relatively Low | 57.9 | — | — | — |
| Lightning | Relatively Low | 37 | 0 | 0 | — |
| Drought | Relatively Low | 39.3 | 0 | 0 | — |
| Landslide | Relatively High | 97.9 | 0 | 0 | — |
| Avalanche | Very Low | 32.3 | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic Activity | Very Low | 33.2 | — | — | — |
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
Big Horn County ranks in the 53rd 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 | 53rd | Moderate |
| Socioeconomic status | 54th | Moderate |
| Household characteristics | 79th | High |
| Racial & ethnic minority status | 40th | Low |
| Housing type & transportation | 31st | Low |
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 | 50th | Relatively Moderate |
| Risk to homes | 58th | Relatively Moderate |
| Buildings in direct exposure zone | 41.4% | — |
NOAA tracked 21 weather events in this county over 2016–2025: 11 in 2016–20 vs 10 in 2021–25 (-9% — relatively stable).
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 Big Horn County?
According to the FEMA National Risk Index, the highest-risk hazards in Big Horn County, Wyoming are landslide, wildfire, and earthquake. The county's overall natural hazard risk is rated Very Low — among the lowest-risk counties in the country.
Has Big Horn County received federal disaster declarations?
Yes. Big Horn County has received 4 federal disaster declarations since 1978, including declarations in 2020. The most common disaster type on record is biological (2 declarations).
Has Big Horn County had any FEMA disaster declarations in 2024, 2025, or 2026?
No federal disaster declarations have been recorded for Big Horn County since the start of 2024. Its most recent declaration on record is Covid-19 in 2020.
How does Big Horn County's natural hazard risk compare to nearby counties?
Among neighboring counties, Sheridan County, WY has the highest overall natural hazard risk (Relatively Low) and Hot Springs County, WY has the lowest (Very Low). Big Horn County is rated Very Low overall.
How is Big Horn County's composite disaster risk index calculated?
Big Horn 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. Big Horn County's composite score of 31 means its overall natural hazard risk is higher than 31% of US counties.