Weber County, Utah Natural Disaster Risk
FEMA National Risk Index assessment · UT
MediumComposite Risk Score
National percentile: 87th
Weber County faces medium composite natural disaster risk (NRI Risk Index score 87.0, 87th national percentile), driven primarily by earthquake and lightning exposure. Expected annual loss across all 18 hazard types is $104M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Weber County at medium composite risk, with a National Risk Index score of 87.0 out of 100 — placing it in the 87th national percentile and near the national midpoint 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 earthquake (ground shaking from sudden movement along geologic faults) at Medium risk — $66M in expected annual loss and about 0.02 events per year; lightning (electrical discharges from storms that ignite fires and cause casualties) at High risk — $3M in expected annual loss and about 32.79 events per year; and wildfire (uncontrolled fires that spread across wildland and into communities) at Medium risk — $4M in expected annual loss and about 0.00 events per year. Across all hazards, FEMA estimates $104M in expected annual loss for a population of 262K.
Beyond physical exposure, Weber 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.
History supports the rating: Weber County has received 11 federal disaster declarations since 1977, including 4 for flood events and 2 for biological events. The most recent was Straight-Line Winds (severe storm), declared in January 2021.
Among 29 Utah counties, Weber County ranks #5 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Earthquake | Medium | 0.02 / yr | $66M |
| Lightning | High | 32.79 / yr | $3M |
| Wildfire | Medium | 0.00 / yr | $4M |
| Avalanche | High | 0.47 / yr | $4M |
| Winter Weather | High | 33.10 / yr | $668K |
| Heat Wave | Medium | 1.17 / yr | $3M |
| Strong Wind | Medium | 1.14 / yr | $2M |
| Riverine Flood | Low | 0.61 / yr | $19M |
| Landslide | Very Low | 0.45 / yr | $2K |
| Cold Wave | Low | 0.17 / yr | $1M |
| Drought | Low | 48.34 / yr | $156K |
| Ice Storm | Low | 0.01 / yr | $61K |
| Tornado | Low | 0.05 / yr | $915K |
| Hail | Very Low | 0.29 / yr | $76K |
| 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
Weber County has received 11 federal disaster declarations since 1977, most recently Straight-Line Winds in January 2021. Most frequent causes: Flood (4), Biological (2), Fire (2).
| Declared | Type | Disaster |
|---|---|---|
| January 2021 | Severe Storm | Straight-Line Winds |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2017 | Fire | Uintah Fire |
| August 2011 | Flood | Flooding |
| September 2005 | Coastal Storm | Hurricane Katrina Evacuation |
| July 2003 | Fire | Ut-Causey Fire 07/14/2003 |
| March 1986 | Flood | Heavy Rains, Snowmelt & Flooding |
| August 1984 | Flood | Severe Storms, Mudslides, Landslides & Flooding |
| April 1983 | Flood | Severe Storms, Landslides & Flooding |
Showing the 10 most recent of 11 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Weber County?
Weber County has a composite FEMA National Risk Index score of 87.0 out of 100, placing it in the Medium category and the 87th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Weber County?
The three highest-rated hazards are Earthquake (Medium, $66M EAL), Lightning (High, $3M EAL), Wildfire (Medium, $4M EAL). These account for most of the county's expected annual losses.
How does Weber County compare to other Utah counties?
Weber County ranks #5 of 29 Utah counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Weber County had?
FEMA records 11 federal disaster declarations for Weber County since 1977, most often 4 for flood events and 2 for biological events. The most recent was Straight-Line Winds, declared in January 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. Weber County's $104M EAL is a statistical average, not a guarantee for any specific year or address.