Jefferson County, MT
FEMA National Risk Index scores, disaster declarations & hazard data
Jefferson County has experienced 11 federally declared disasters since 1975, most recently Covid-19 in 2020. Its overall natural hazard risk is rated Very Low — among the lowest-risk counties in the country.
Jefferson County's highest-rated hazards are landslide, wildfire, and winter weather, with its top risk rated "Relatively Moderate" by FEMA's National Risk Index. Recorded storm events have decreased 61% over the past five years compared to the prior five-year period. Community vulnerability is relatively low (12th percentile nationally), indicating stronger recovery capacity than most US counties.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Jefferson County has been designated in 11 declarations since 1975, covering 5 disaster types including fire (3), flood (3), biological (2).
| Year | Type | Event name |
|---|---|---|
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2014 | Flood | Ice Jams And Flooding |
| 2012 | Fire | Nineteen Mile Fire |
| 2011 | Severe Storm | Severe Storms And Flooding |
| 2005 | Hurricane | Hurricane Katrina Evacuation |
| 2000 | Fire | Wildfires |
| 2000 | Fire | Mt - Central Zone 3b Fire Complex |
| 1996 | Severe Storm | Severe Storms, Flooding, And Ice Jams |
| 1981 | Flood | Severe Storms & Flooding |
Showing the 10 most recent of 11 total declarations since 1975.
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 | 89.1 | 0 | 0 | — |
| Inland Flooding | Very Low | 29.4 | 4 | 0 | $100K |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Relatively Low | 64.8 | 17 | — | — |
| Heat Wave | Very Low | 10.1 | 0 | 0 | — |
| Tornado | Very Low | 5.7 | 1 | 0 | — |
| Hurricane | Not Applicable | — | 0 | 0 | — |
| Hail | Very Low | 19.6 | 20 | 0 | — |
| Strong Wind | Very Low | 7.1 | 0 | 0 | — |
| Winter Weather | Relatively Moderate | 78.3 | 0 | 0 | — |
| Ice Storm | Very Low | 7 | — | — | — |
| Cold Wave | Relatively Low | 62.7 | — | — | — |
| Lightning | Relatively Moderate | 59 | 0 | 0 | — |
| Drought | Very Low | 19.8 | 0 | 0 | — |
| Landslide | Relatively Moderate | 95.9 | 0 | 0 | — |
| Avalanche | Very Low | 16.8 | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic Activity | Not Applicable | — | — | — | — |
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
Jefferson County ranks in the 12th percentile (Very low) 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 | 12th | Very low |
| Socioeconomic status | 8th | Very low |
| Household characteristics | 18th | Very low |
| Racial & ethnic minority status | 24th | Very low |
| Housing type & transportation | 35th | 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 | 82nd | Very High |
| Risk to homes | 87th | Very High |
| Buildings in direct exposure zone | 81.2% | — |
NOAA tracked 25 weather events in this county over 2016–2025: 18 in 2016–20 vs 7 in 2021–25 (-61% — 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 Jefferson County?
According to the FEMA National Risk Index, the highest-risk hazards in Jefferson County, Montana are landslide, wildfire, and winter weather. The county's overall natural hazard risk is rated Very Low — among the lowest-risk counties in the country.
Has Jefferson County received federal disaster declarations?
Yes. Jefferson County has received 11 federal disaster declarations since 1975, including declarations in 2020. The most common disaster type on record is fire (3 declarations).
Has Jefferson County had any FEMA disaster declarations in 2024, 2025, or 2026?
No federal disaster declarations have been recorded for Jefferson County since the start of 2024. Its most recent declaration on record is Covid-19 in 2020.
How does Jefferson County's natural hazard risk compare to nearby counties?
Among neighboring counties, Gallatin County, MT has the highest overall natural hazard risk (Relatively Moderate) and Meagher County, MT has the lowest (Very Low). Jefferson County is rated Very Low overall.
How is Jefferson County's composite disaster risk index calculated?
Jefferson 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. Jefferson County's composite score of 22 means its overall natural hazard risk is higher than 22% of US counties.