Sweetwater County, Wyoming Natural Disaster Risk
FEMA National Risk Index assessment · WY
Very LowComposite Risk Score
National percentile: 31th
Sweetwater County faces very low composite natural disaster risk (NRI Risk Index score 30.6, 31th national percentile), driven primarily by landslide and winter weather exposure. Expected annual loss across all 18 hazard types is $12M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Sweetwater County carries a very low composite natural disaster risk, with a National Risk Index score of 30.6 out of 100 — placing it in the 31st 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 Medium risk — $71K in expected annual loss and about 2.61 events per year; winter weather (heavy snow, blizzards, and hazardous winter conditions) at High risk — $339K in expected annual loss and about 13.01 events per year; and wildfire (uncontrolled fires that spread across wildland and into communities) at Low risk — $151K in expected annual loss and about 0.00 events per year. Across all hazards, FEMA estimates $12M in expected annual loss for a population of 42K.
Beyond physical exposure, Sweetwater County has a very low social vulnerability rating (how susceptible the population is to harm) and a very low 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: Sweetwater County has received 4 federal disaster declarations since 1977, including 2 for biological events and 1 for severe storm events. The most recent was Covid-19 Pandemic (biological), declared in April 2020.
Among 23 Wyoming counties, Sweetwater County ranks #13 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | Medium | 2.61 / yr | $71K |
| Winter Weather | High | 13.01 / yr | $339K |
| Wildfire | Low | 0.00 / yr | $151K |
| Earthquake | Low | 0.00 / yr | $728K |
| Cold Wave | Low | 1.19 / yr | $2M |
| Lightning | Low | 38.54 / yr | $337K |
| Riverine Flood | Low | 0.39 / yr | $8M |
| Drought | Very Low | 119.96 / yr | $4K |
| Ice Storm | Very Low | 0.01 / yr | $13K |
| Hail | Very Low | 0.07 / yr | $56K |
| Avalanche | Very Low | 0.01 / yr | $14 |
| Strong Wind | Very Low | 0.19 / yr | $87K |
| Tornado | Very Low | 0.36 / yr | $66K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Heat Wave | 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
Sweetwater County has received 4 federal disaster declarations since 1977, most recently Covid-19 Pandemic in April 2020. Most frequent causes: Biological (2), Severe Storm (1), Drought (1).
| Declared | Type | Disaster |
|---|---|---|
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| July 2011 | Severe Storm | Severe Storms, Flooding, and Landslides |
| June 1977 | Drought | Drought |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Sweetwater County?
Sweetwater County has a composite FEMA National Risk Index score of 30.6 out of 100, placing it in the Very Low category and the 31th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Sweetwater County?
The three highest-rated hazards are Landslide (Medium, $71K EAL), Winter Weather (High, $339K EAL), Wildfire (Low, $151K EAL). These account for most of the county's expected annual losses.
How does Sweetwater County compare to other Wyoming counties?
Sweetwater County ranks #13 of 23 Wyoming counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Sweetwater County had?
FEMA records 4 federal disaster declarations for Sweetwater County since 1977, most often 2 for biological events and 1 for severe 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. Sweetwater County's $12M EAL is a statistical average, not a guarantee for any specific year or address.