Flathead County, Montana Natural Disaster Risk
FEMA National Risk Index assessment · MT
MediumComposite Risk Score
National percentile: 86th
Flathead County faces medium composite natural disaster risk (NRI Risk Index score 86.5, 86th national percentile), driven primarily by avalanche and landslide exposure. Expected annual loss across all 18 hazard types is $75M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Flathead County is medium, with a National Risk Index score of 86.5 out of 100 — placing it in the 86th national percentile and near the national midpoint for natural-disaster risk. 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 avalanche (fast-moving snow and debris sliding down steep mountain slopes) at Very High risk — $9M in expected annual loss and about 0.50 events per year; landslide (downhill movement of rock, soil, and debris on unstable slopes) at Medium risk — $417K in expected annual loss and about 4.16 events per year; and earthquake (ground shaking from sudden movement along geologic faults) at Medium risk — $21M in expected annual loss and about 0.03 events per year. Across all hazards, FEMA estimates $75M in expected annual loss for a population of 104K.
Beyond physical exposure, Flathead 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: Flathead County has received 15 federal disaster declarations since 1974, including 5 for fire events and 3 for flood events. The most recent was Severe Winter Storm and Straight-Line Winds (straight-line winds), declared in April 2026.
Among 56 Montana counties, Flathead County ranks #1 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Avalanche | Very High | 0.50 / yr | $9M |
| Landslide | Medium | 4.16 / yr | $417K |
| Earthquake | Medium | 0.03 / yr | $21M |
| Wildfire | Medium | 0.00 / yr | $5M |
| Cold Wave | High | 4.19 / yr | $14M |
| Winter Weather | High | 50.08 / yr | $725K |
| Riverine Flood | Medium | 1.00 / yr | $24M |
| Ice Storm | Medium | 0.01 / yr | $264K |
| Lightning | Medium | 20.85 / yr | $392K |
| Heat Wave | Low | 1.30 / yr | $632K |
| Drought | Very Low | 36.01 / yr | $14K |
| Hail | Very Low | 0.33 / yr | $96K |
| Strong Wind | Very Low | 0.18 / yr | $146K |
| Tornado | Very Low | 0.07 / yr | $19K |
| 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
Flathead County has received 15 federal disaster declarations since 1974, most recently Severe Winter Storm and Straight-Line Winds in April 2026. Most frequent causes: Fire (5), Flood (3), Severe Storm (3).
| 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 |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| August 2003 | Fire | Mt-Flathead Fire Zone-8/20/03 |
| July 2003 | Fire | Mt-Wedge Canyon Fire-07/18/2003 |
| July 2003 | Fire | Mt-Robert Fire-07-23-03 |
| August 2000 | Fire | Wildfires |
Showing the 10 most recent of 15 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Flathead County?
Flathead County has a composite FEMA National Risk Index score of 86.5 out of 100, placing it in the Medium category and the 86th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Flathead County?
The three highest-rated hazards are Avalanche (Very High, $9M EAL), Landslide (Medium, $417K EAL), Earthquake (Medium, $21M EAL). These account for most of the county's expected annual losses.
How does Flathead County compare to other Montana counties?
Flathead County ranks #1 of 56 Montana counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Flathead County had?
FEMA records 15 federal disaster declarations for Flathead County since 1974, most often 5 for fire events and 3 for flood 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. Flathead County's $75M EAL is a statistical average, not a guarantee for any specific year or address.