Granite County, Montana Natural Disaster Risk
FEMA National Risk Index assessment · MT
Very LowComposite Risk Score
National percentile: 9th
Granite County faces very low composite natural disaster risk (NRI Risk Index score 9.4, 9th national percentile), driven primarily by landslide and wildfire exposure. Expected annual loss across all 18 hazard types is $4M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Granite County carries a very low composite natural disaster risk, with a National Risk Index score of 9.4 out of 100 — placing it in the 9th 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.
Risk here concentrates in landslide (downhill movement of rock, soil, and debris on unstable slopes) at Medium risk — $68K in expected annual loss and about 1.17 events per year; wildfire (uncontrolled fires that spread across wildland and into communities) at Low risk — $1M in expected annual loss and about 0.01 events per year; and avalanche (fast-moving snow and debris sliding down steep mountain slopes) at High risk — $1M in expected annual loss and about 0.20 events per year. Across all hazards, FEMA estimates $4M in expected annual loss for a population of 3K.
Beyond physical exposure, Granite County has a medium social vulnerability rating (how susceptible the population is to harm) and a low community resilience rating (its capacity to prepare for and recover from disasters). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
History supports the rating: Granite County has received 8 federal disaster declarations since 1981, including 2 for biological events and 2 for fire events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 56 Montana counties, Granite County ranks #40 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | Medium | 1.17 / yr | $68K |
| Wildfire | Low | 0.01 / yr | $1M |
| Avalanche | High | 0.20 / yr | $1M |
| Winter Weather | Low | 52.58 / yr | $56K |
| Earthquake | Very Low | 0.01 / yr | $120K |
| Cold Wave | Low | 2.94 / yr | $470K |
| Ice Storm | Low | 0.14 / yr | $27K |
| Drought | Very Low | 46.64 / yr | $2K |
| Riverine Flood | Very Low | 0.29 / yr | $1M |
| Lightning | Very Low | 27.85 / yr | $24K |
| Hail | Very Low | 0.60 / yr | $17K |
| Heat Wave | Very Low | 0.38 / yr | $4K |
| Strong Wind | Very Low | 0.29 / yr | $15K |
| Tornado | Very Low | 0.03 / yr | $5K |
| 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
Granite County has received 8 federal disaster declarations since 1981, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Biological (2), Fire (2), Flood (2).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| June 2011 | Severe Storm | Severe Storms and Flooding |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| August 2000 | Fire | Wildfires |
| August 2000 | Fire | Mt-Southwestern Zone Two Fire Complex |
| March 1986 | Flood | Heavy Rains, Landslides & Flooding |
| May 1981 | Flood | Severe Storms & Flooding |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Granite County?
Granite County has a composite FEMA National Risk Index score of 9.4 out of 100, placing it in the Very Low category and the 9th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Granite County?
The three highest-rated hazards are Landslide (Medium, $68K EAL), Wildfire (Low, $1M EAL), Avalanche (High, $1M EAL). These account for most of the county's expected annual losses.
How does Granite County compare to other Montana counties?
Granite County ranks #40 of 56 Montana counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Granite County had?
FEMA records 8 federal disaster declarations for Granite County since 1981, most often 2 for biological events and 2 for fire events. The most recent was Covid-19 Pandemic, declared in March 2020.
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. Granite County's $4M EAL is a statistical average, not a guarantee for any specific year or address.