Sweet Grass County, Montana Natural Disaster Risk
FEMA National Risk Index assessment · MT
Very LowComposite Risk Score
National percentile: 8th
Sweet Grass County faces very low composite natural disaster risk (NRI Risk Index score 8.1, 8th national percentile), driven primarily by wildfire and avalanche exposure. Expected annual loss across all 18 hazard types is $6M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Sweet Grass County at very low composite risk, with a National Risk Index score of 8.1 out of 100 — placing it in the 8th national percentile and among the lowest-risk counties in the country. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
The county's risk is driven primarily by wildfire (uncontrolled fires that spread across wildland and into communities) at Low risk — $1M in expected annual loss and about 0.00 events per year; avalanche (fast-moving snow and debris sliding down steep mountain slopes) at Very Low risk — $2K in expected annual loss and about 0.13 events per year; and landslide (downhill movement of rock, soil, and debris on unstable slopes) at Very Low risk — $3K in expected annual loss and about 2.27 events per year. Across all hazards, FEMA estimates $6M in expected annual loss for a population of 4K.
Beyond physical exposure, Sweet Grass County has a very low social vulnerability rating (how susceptible the population is to harm) and a medium community resilience rating (its capacity to prepare for and recover from disasters). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
The federal record bears this out: Sweet Grass County has received 10 federal disaster declarations since 1997, including 3 for fire events and 2 for biological events. The most recent was Severe Winter Storm and Straight-Line Winds (straight-line winds), declared in April 2026.
Among 56 Montana counties, Sweet Grass County ranks #41 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Wildfire | Low | 0.00 / yr | $1M |
| Avalanche | Very Low | 0.13 / yr | $2K |
| Landslide | Very Low | 2.27 / yr | $3K |
| Earthquake | Very Low | 0.00 / yr | $157K |
| Winter Weather | Low | 22.68 / yr | $46K |
| Cold Wave | Low | 2.41 / yr | $578K |
| Hail | Very Low | 1.32 / yr | $109K |
| Riverine Flood | Very Low | 0.39 / yr | $3M |
| Lightning | Very Low | 36.08 / yr | $88K |
| Drought | Very Low | 65.68 / yr | $4K |
| Heat Wave | Very Low | 0.75 / yr | $13K |
| Ice Storm | Very Low | 0.01 / yr | $2K |
| Tornado | Very Low | 0.06 / yr | $16K |
| Strong Wind | Very Low | 0.60 / yr | $25K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Sweet Grass County has received 10 federal disaster declarations since 1997, most recently Severe Winter Storm and Straight-Line Winds in April 2026. Most frequent causes: Fire (3), Biological (2), Severe Storm (2).
| Declared | Type | Disaster |
|---|---|---|
| April 2026 | Straight-Line Winds | Severe Winter Storm and Straight-Line Winds |
| June 2022 | Flood | Severe Storm and Flooding |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| June 2011 | Severe Storm | Severe Storms and Flooding |
| August 2006 | Fire | Derby Fire |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| August 2003 | Fire | Mt-Hobble Fire-08/07/2003 |
| August 2000 | Fire | Wildfires |
| July 1997 | Severe Storm | Severe Storms,Ice Jams, Snow Melt, Flooding |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Sweet Grass County?
Sweet Grass County has a composite FEMA National Risk Index score of 8.1 out of 100, placing it in the Very Low category and the 8th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Sweet Grass County?
The three highest-rated hazards are Wildfire (Low, $1M EAL), Avalanche (Very Low, $2K EAL), Landslide (Very Low, $3K EAL). These account for most of the county's expected annual losses.
How does Sweet Grass County compare to other Montana counties?
Sweet Grass County ranks #41 of 56 Montana counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Sweet Grass County had?
FEMA records 10 federal disaster declarations for Sweet Grass County since 1997, most often 3 for fire events and 2 for biological events. The most recent was Severe Winter Storm and Straight-Line Winds, declared in April 2026.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Sweet Grass County's $6M EAL is a statistical average, not a guarantee for any specific year or address.