Big Horn County, MT
FEMA National Risk Index scores, disaster declarations & hazard data
Big Horn County has experienced 9 federally declared disasters since 1978, most recently Severe Winter Storm And Straight-Line Winds in 2026. Its overall natural hazard risk is rated Relatively Low — lower risk than most US counties.
Big Horn County's highest-rated hazards are strong wind, wildfire, and winter weather, with its top risk rated "Relatively High" by FEMA's National Risk Index. Recorded storm events have decreased 26% over the past five years compared to the prior five-year period. Community vulnerability is elevated (76th percentile nationally), suggesting residents may face greater difficulty recovering from major disasters.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Big Horn County has been designated in 9 declarations since 1978, covering 6 disaster types including fire (2), biological (2), severe storm (2).
| Year | Type | Event name |
|---|---|---|
| 2026 | Straight-Line Winds | Severe Winter Storm And Straight-Line Winds |
| 2021 | Fire | Pf Fire |
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2011 | Severe Storm | Severe Storms And Flooding |
| 2005 | Hurricane | Hurricane Katrina Evacuation |
| 2001 | Severe Storm | Severe Winter Storms |
| 2000 | Fire | Wildfires |
| 1978 | Flood | Severe Storms & 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 | 94.8 | 0 | 0 | — |
| Inland Flooding | Relatively Low | 55.1 | 4 | 0 | — |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Very Low | 39.6 | 7 | — | — |
| Heat Wave | Very Low | 34.9 | 0 | 0 | — |
| Tornado | Very Low | 12.1 | 1 | 0 | — |
| Hurricane | Not Applicable | — | 0 | 0 | — |
| Hail | Relatively Low | 51.8 | 54 | 0 | — |
| Strong Wind | Relatively High | 95.9 | 0 | 0 | — |
| Winter Weather | Relatively High | 88.5 | 0 | 0 | — |
| Ice Storm | Very Low | 12.5 | — | — | — |
| Cold Wave | Relatively Moderate | 76.9 | — | — | — |
| Lightning | Relatively High | 83.2 | 0 | 0 | — |
| Drought | Relatively Low | 38.5 | 0 | 0 | — |
| Landslide | Relatively Low | 73.8 | 0 | 0 | — |
| Avalanche | Very Low | 36.3 | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic Activity | Very Low | 9.4 | — | — | — |
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 76th percentile (High) 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 | 76th | High |
| Socioeconomic status | 89th | High |
| Household characteristics | 10th | Very low |
| Racial & ethnic minority status | 97th | High |
| Housing type & transportation | 77th | High |
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 | 95th | Very High |
| Risk to homes | 93rd | Very High |
| Buildings in direct exposure zone | 61.6% | — |
NOAA tracked 59 weather events in this county over 2016–2025: 34 in 2016–20 vs 25 in 2021–25 (-26% — frequency decreasing).
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, Montana are strong wind, wildfire, and winter weather. The county's overall natural hazard risk is rated Relatively Low — lower risk than most US counties.
Has Big Horn County received federal disaster declarations?
Yes. Big Horn County has received 9 federal disaster declarations since 1978, including declarations in 2026. The most common disaster type on record is fire (2 declarations).
Has Big Horn County had any FEMA disaster declarations in 2024, 2025, or 2026?
Yes. Recent federal disaster declarations for Big Horn County include Severe Winter Storm And Straight-Line Winds (2026). See the declarations table above for the full history since 1978.
How does Big Horn County's natural hazard risk compare to nearby counties?
Among neighboring counties, Yellowstone County, MT has the highest overall natural hazard risk (Relatively Moderate) and Treasure County, MT has the lowest (Very Low). Big Horn County is rated Relatively 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 57 means its overall natural hazard risk is higher than 57% of US counties.