Custer County, Montana Natural Disaster Risk
FEMA National Risk Index assessment · MT
Very LowComposite Risk Score
National percentile: 42th
Custer County faces very low composite natural disaster risk (NRI Risk Index score 42.1, 42th national percentile), driven primarily by cold wave and winter weather exposure. Expected annual loss across all 18 hazard types is $10M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Custer County is very low, with a National Risk Index score of 42.1 out of 100 — placing it in the 42nd 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.
Most of Custer County's expected losses come from cold wave (prolonged spells of dangerously low temperatures) at Medium risk — $4M in expected annual loss and about 6.32 events per year; winter weather (heavy snow, blizzards, and hazardous winter conditions) at High risk — $230K in expected annual loss and about 15.79 events per year; and wildfire (uncontrolled fires that spread across wildland and into communities) at Low risk — $550K in expected annual loss and about 0.01 events per year. Across all hazards, FEMA estimates $10M in expected annual loss for a population of 12K.
Beyond physical exposure, Custer County has a high 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). That combination — a more vulnerable population with limited resilience — can amplify the human cost of any given event.
The county's disaster history tells the same story: Custer County has received 9 federal disaster declarations since 2000, including 2 for fire events and 2 for biological events. The most recent was Snider/Rice Fire Complex (fire), declared in September 2020.
Among 56 Montana counties, Custer County ranks #23 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Cold Wave | Medium | 6.32 / yr | $4M |
| Winter Weather | High | 15.79 / yr | $230K |
| Wildfire | Low | 0.01 / yr | $550K |
| Lightning | Medium | 31.02 / yr | $493K |
| Strong Wind | Medium | 0.97 / yr | $575K |
| Landslide | Very Low | 2.88 / yr | $2K |
| Hail | Low | 1.78 / yr | $184K |
| Heat Wave | Very Low | 2.21 / yr | $162K |
| Riverine Flood | Low | 0.93 / yr | $4M |
| Earthquake | Very Low | 0.00 / yr | $68K |
| Drought | Very Low | 61.45 / yr | $13K |
| Tornado | Very Low | 0.26 / yr | $126K |
| Ice Storm | Very Low | 0.01 / yr | $4K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| 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
Custer County has received 9 federal disaster declarations since 2000, most recently Snider/Rice Fire Complex in September 2020. Most frequent causes: Fire (2), Biological (2), Flood (2).
| Declared | Type | Disaster |
|---|---|---|
| September 2020 | Fire | Snider/Rice Fire Complex |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| October 2018 | Flood | Flooding |
| July 2013 | Flood | Flooding |
| June 2011 | Severe Storm | Severe Storms and Flooding |
| June 2008 | Severe Storm | Severe Winter Storm |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| August 2000 | Fire | Wildfires |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Custer County?
Custer County has a composite FEMA National Risk Index score of 42.1 out of 100, placing it in the Very Low category and the 42th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Custer County?
The three highest-rated hazards are Cold Wave (Medium, $4M EAL), Winter Weather (High, $230K EAL), Wildfire (Low, $550K EAL). These account for most of the county's expected annual losses.
How does Custer County compare to other Montana counties?
Custer County ranks #23 of 56 Montana counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Custer County had?
FEMA records 9 federal disaster declarations for Custer County since 2000, most often 2 for fire events and 2 for biological events. The most recent was Snider/Rice Fire Complex, declared in September 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. Custer County's $10M EAL is a statistical average, not a guarantee for any specific year or address.