Valley County, Montana Natural Disaster Risk
FEMA National Risk Index assessment · MT
Very LowComposite Risk Score
National percentile: 36th
Valley County faces very low composite natural disaster risk (NRI Risk Index score 35.9, 36th national percentile), driven primarily by hail and cold wave exposure. Expected annual loss across all 18 hazard types is $11M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Valley County carries a very low composite natural disaster risk, with a National Risk Index score of 35.9 out of 100 — placing it in the 36th 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 hail (ice stones from severe thunderstorms that damage property and crops) at Medium risk — $1M in expected annual loss and about 1.39 events per year; cold wave (prolonged spells of dangerously low temperatures) at Medium risk — $5M in expected annual loss and about 19.30 events per year; and winter weather (heavy snow, blizzards, and hazardous winter conditions) at Medium risk — $94K in expected annual loss and about 18.58 events per year. Across all hazards, FEMA estimates $11M in expected annual loss for a population of 8K.
Beyond physical exposure, Valley County has a medium 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.
History supports the rating: Valley County has received 13 federal disaster declarations since 1986, including 6 for flood events and 3 for severe storm events. The most recent was Severe Winter Storm and Straight-Line Winds (straight-line winds), declared in April 2026.
Among 56 Montana counties, Valley County ranks #27 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Hail | Medium | 1.39 / yr | $1M |
| Cold Wave | Medium | 19.30 / yr | $5M |
| Winter Weather | Medium | 18.58 / yr | $94K |
| Wildfire | Very Low | 0.00 / yr | $45K |
| Landslide | Very Low | 1.24 / yr | $751 |
| Drought | Low | 36.84 / yr | $53K |
| Riverine Flood | Very Low | 3.00 / yr | $4M |
| Heat Wave | Very Low | 2.42 / yr | $98K |
| Earthquake | Very Low | 0.00 / yr | $36K |
| Strong Wind | Low | 1.33 / yr | $148K |
| Lightning | Very Low | 25.78 / yr | $52K |
| Tornado | Very Low | 0.43 / yr | $134K |
| 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
Valley County has received 13 federal disaster declarations since 1986, most recently Severe Winter Storm and Straight-Line Winds in April 2026. Most frequent causes: Flood (6), Severe Storm (3), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| April 2026 | Straight-Line Winds | Severe Winter Storm and Straight-Line Winds |
| August 2023 | Flood | Flooding |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| May 2019 | Flood | Flooding |
| August 2018 | Flood | Flooding |
| October 2014 | Severe Storm | Severe Storms, Straight-Line Winds, and Flooding |
| July 2013 | Flood | Flooding |
| June 2011 | Severe Storm | Severe Storms and Flooding |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
Showing the 10 most recent of 13 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Valley County?
Valley County has a composite FEMA National Risk Index score of 35.9 out of 100, placing it in the Very Low category and the 36th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Valley County?
The three highest-rated hazards are Hail (Medium, $1M EAL), Cold Wave (Medium, $5M EAL), Winter Weather (Medium, $94K EAL). These account for most of the county's expected annual losses.
How does Valley County compare to other Montana counties?
Valley County ranks #27 of 56 Montana counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Valley County had?
FEMA records 13 federal disaster declarations for Valley County since 1986, most often 6 for flood events and 3 for severe storm 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. Valley County's $11M EAL is a statistical average, not a guarantee for any specific year or address.