Summit County, Utah Natural Disaster Risk
FEMA National Risk Index assessment · UT
LowComposite Risk Score
National percentile: 60th
Summit County faces low composite natural disaster risk (NRI Risk Index score 60.1, 60th national percentile), driven primarily by avalanche and wildfire exposure. Expected annual loss across all 18 hazard types is $39M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Summit County is low, with a National Risk Index score of 60.1 out of 100 — placing it in the 60th national percentile and below the national average 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 — $10M in expected annual loss and about 1.53 events per year; wildfire (uncontrolled fires that spread across wildland and into communities) at Medium risk — $11M in expected annual loss and about 0.00 events per year; and landslide (downhill movement of rock, soil, and debris on unstable slopes) at Medium risk — $141K in expected annual loss and about 1.40 events per year. Across all hazards, FEMA estimates $39M in expected annual loss for a population of 42K.
Beyond physical exposure, Summit County has a very low social vulnerability rating (how susceptible the population is to harm) and a very high community resilience rating (its capacity to prepare for and recover from disasters). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
The federal record bears this out: Summit County has received 9 federal disaster declarations since 1977, including 3 for flood events and 2 for fire events. The most recent was Parleys Canyon Fire (fire), declared in August 2021.
Among 29 Utah counties, Summit County ranks #8 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Avalanche | Very High | 1.53 / yr | $10M |
| Wildfire | Medium | 0.00 / yr | $11M |
| Landslide | Medium | 1.40 / yr | $141K |
| Lightning | High | 43.10 / yr | $2M |
| Winter Weather | High | 51.30 / yr | $587K |
| Strong Wind | Medium | 0.70 / yr | $1M |
| Earthquake | Very Low | 0.01 / yr | $670K |
| Riverine Flood | Low | 0.21 / yr | $12M |
| Volcanic Activity | Very Low | 0.00 / yr | $10 |
| Drought | Very Low | 75.21 / yr | $31K |
| Heat Wave | Very Low | 0.05 / yr | $57K |
| Ice Storm | Very Low | 0.01 / yr | $15K |
| Tornado | Very Low | 0.11 / yr | $209K |
| Hail | Very Low | 0.24 / yr | $55K |
| Cold Wave | Very Low | 0.07 / yr | $102K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Summit County has received 9 federal disaster declarations since 1977, most recently Parleys Canyon Fire in August 2021. Most frequent causes: Flood (3), Fire (2), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| August 2021 | Fire | Parleys Canyon Fire |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| August 2013 | Fire | Rockport Five Fire |
| August 2011 | Flood | Flooding |
| September 2005 | Coastal Storm | Hurricane Katrina Evacuation |
| 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 Summit County?
Summit County has a composite FEMA National Risk Index score of 60.1 out of 100, placing it in the Low category and the 60th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Summit County?
The three highest-rated hazards are Avalanche (Very High, $10M EAL), Wildfire (Medium, $11M EAL), Landslide (Medium, $141K EAL). These account for most of the county's expected annual losses.
How does Summit County compare to other Utah counties?
Summit County ranks #8 of 29 Utah counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Summit County had?
FEMA records 9 federal disaster declarations for Summit County since 1977, most often 3 for flood events and 2 for fire events. The most recent was Parleys Canyon Fire, declared in August 2021.
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. Summit County's $39M EAL is a statistical average, not a guarantee for any specific year or address.