Carbon County, Utah Natural Disaster Risk
FEMA National Risk Index assessment · UT
Very LowComposite Risk Score
National percentile: 9th
Carbon County faces very low composite natural disaster risk (NRI Risk Index score 8.7, 9th national percentile), driven primarily by landslide and lightning exposure. Expected annual loss across all 18 hazard types is $5M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Carbon County is very low, with a National Risk Index score of 8.7 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.
The county's risk is driven primarily by landslide (downhill movement of rock, soil, and debris on unstable slopes) at Low risk — $16K in expected annual loss and about 1.66 events per year; lightning (electrical discharges from storms that ignite fires and cause casualties) at Medium risk — $541K in expected annual loss and about 51.72 events per year; and wildfire (uncontrolled fires that spread across wildland and into communities) at Low risk — $140K in expected annual loss and about 0.00 events per year. Across all hazards, FEMA estimates $5M in expected annual loss for a population of 20K.
Beyond physical exposure, Carbon County has a 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: Carbon County has received 5 federal disaster declarations since 1977, including 2 for biological events and 1 for coastal storm events. The most recent was Covid-19 Pandemic (biological), declared in April 2020.
Among 29 Utah counties, Carbon County ranks #21 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | Low | 1.66 / yr | $16K |
| Lightning | Medium | 51.72 / yr | $541K |
| Wildfire | Low | 0.00 / yr | $140K |
| Earthquake | Low | 0.01 / yr | $623K |
| Avalanche | Very Low | 0.03 / yr | $2K |
| Winter Weather | Medium | 28.25 / yr | $103K |
| Volcanic Activity | Very Low | 0.00 / yr | $5 |
| Drought | Very Low | 89.15 / yr | $29K |
| Heat Wave | Very Low | 0.42 / yr | $110K |
| Riverine Flood | Very Low | 0.61 / yr | $3M |
| Tornado | Very Low | 0.05 / yr | $101K |
| Ice Storm | Very Low | 0.01 / yr | $4K |
| Strong Wind | Very Low | 0.21 / yr | $45K |
| Hail | Very Low | 0.14 / yr | $8K |
| Cold Wave | 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 |
Disaster History
Carbon County has received 5 federal disaster declarations since 1977, most recently Covid-19 Pandemic in April 2020. Most frequent causes: Biological (2), Coastal Storm (1), Flood (1).
| Declared | Type | Disaster |
|---|---|---|
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2005 | Coastal Storm | Hurricane Katrina Evacuation |
| 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 Carbon County?
Carbon County has a composite FEMA National Risk Index score of 8.7 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 Carbon County?
The three highest-rated hazards are Landslide (Low, $16K EAL), Lightning (Medium, $541K EAL), Wildfire (Low, $140K EAL). These account for most of the county's expected annual losses.
How does Carbon County compare to other Utah counties?
Carbon County ranks #21 of 29 Utah counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Carbon County had?
FEMA records 5 federal disaster declarations for Carbon County since 1977, most often 2 for biological events and 1 for coastal storm events. The most recent was Covid-19 Pandemic, declared in April 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. Carbon County's $5M EAL is a statistical average, not a guarantee for any specific year or address.