Sevier County, Utah Natural Disaster Risk
FEMA National Risk Index assessment · UT
Very LowComposite Risk Score
National percentile: 23th
Sevier County faces very low composite natural disaster risk (NRI Risk Index score 22.7, 23th national percentile), driven primarily by earthquake and avalanche exposure. Expected annual loss across all 18 hazard types is $10M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Sevier County carries a very low composite natural disaster risk, with a National Risk Index score of 22.7 out of 100 — placing it in the 23rd 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 earthquake (ground shaking from sudden movement along geologic faults) at Low risk — $4M in expected annual loss and about 0.02 events per year; avalanche (fast-moving snow and debris sliding down steep mountain slopes) at Medium risk — $691K in expected annual loss and about 0.17 events per year; and landslide (downhill movement of rock, soil, and debris on unstable slopes) at Low risk — $20K in expected annual loss and about 2.50 events per year. Across all hazards, FEMA estimates $10M in expected annual loss for a population of 21K.
Beyond physical exposure, Sevier 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: Sevier County has received 9 federal disaster declarations since 1977, including 4 for flood events and 2 for biological events. The most recent was Monroe Canyon Fire (fire), declared in July 2025.
Among 29 Utah counties, Sevier County ranks #16 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Earthquake | Low | 0.02 / yr | $4M |
| Avalanche | Medium | 0.17 / yr | $691K |
| Landslide | Low | 2.50 / yr | $20K |
| Wildfire | Low | 0.00 / yr | $452K |
| Lightning | Medium | 45.11 / yr | $657K |
| Winter Weather | Medium | 29.69 / yr | $164K |
| Drought | Low | 83.56 / yr | $229K |
| Volcanic Activity | Very Low | 0.00 / yr | $10 |
| Heat Wave | Very Low | 0.30 / yr | $152K |
| Riverine Flood | Very Low | 0.50 / yr | $3M |
| Ice Storm | Very Low | 0.01 / yr | $6K |
| Strong Wind | Very Low | 0.11 / yr | $66K |
| Tornado | Very Low | 0.04 / yr | $28K |
| Cold Wave | Very Low | 0.00 / yr | $0 |
| Hail | Very Low | 0.08 / yr | $2K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Sevier County has received 9 federal disaster declarations since 1977, most recently Monroe Canyon Fire in July 2025. Most frequent causes: Flood (4), Biological (2), Fire (1).
| Declared | Type | Disaster |
|---|---|---|
| July 2025 | Fire | Monroe Canyon Fire |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| August 2011 | Flood | Flooding |
| September 2005 | Coastal Storm | Hurricane Katrina Evacuation |
| August 2005 | Flood | Flooding and Landslides |
| August 1984 | Flood | Severe Storms, Mudslides, Landslides & Flooding |
| April 1983 | Flood | Severe Storms, Landslides & Flooding |
| January 1977 | Drought | Drought |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Sevier County?
Sevier County has a composite FEMA National Risk Index score of 22.7 out of 100, placing it in the Very Low category and the 23th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Sevier County?
The three highest-rated hazards are Earthquake (Low, $4M EAL), Avalanche (Medium, $691K EAL), Landslide (Low, $20K EAL). These account for most of the county's expected annual losses.
How does Sevier County compare to other Utah counties?
Sevier County ranks #16 of 29 Utah counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Sevier County had?
FEMA records 9 federal disaster declarations for Sevier County since 1977, most often 4 for flood events and 2 for biological events. The most recent was Monroe Canyon Fire, declared in July 2025.
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. Sevier County's $10M EAL is a statistical average, not a guarantee for any specific year or address.