San Juan County, Colorado Natural Disaster Risk
FEMA National Risk Index assessment · CO
Very LowComposite Risk Score
National percentile: 11th
San Juan County faces very low composite natural disaster risk (NRI Risk Index score 10.7, 11th national percentile), driven primarily by avalanche and landslide exposure. Expected annual loss across all 18 hazard types is $7M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in San Juan County is very low, with a National Risk Index score of 10.7 out of 100 — placing it in the 11th 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.
Most of San Juan County's expected losses come from avalanche (fast-moving snow and debris sliding down steep mountain slopes) at Very High risk — $6M in expected annual loss and about 0.80 events per year; landslide (downhill movement of rock, soil, and debris on unstable slopes) at Low risk — $5K in expected annual loss and about 0.33 events per year; and lightning (electrical discharges from storms that ignite fires and cause casualties) at Low risk — $196K in expected annual loss and about 55.22 events per year. Across all hazards, FEMA estimates $7M in expected annual loss for a population of 699.
Beyond physical exposure, San Juan 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 county's disaster history tells the same story: San Juan County has received 6 federal disaster declarations since 1970, including 2 for biological events and 2 for flood events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 64 Colorado counties, San Juan County ranks #52 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Avalanche | Very High | 0.80 / yr | $6M |
| Landslide | Low | 0.33 / yr | $5K |
| Lightning | Low | 55.22 / yr | $196K |
| Wildfire | Very Low | 0.00 / yr | $25K |
| Earthquake | Very Low | 0.00 / yr | $15K |
| Winter Weather | Very Low | 44.95 / yr | $5K |
| Riverine Flood | Very Low | 0.18 / yr | $860K |
| Tornado | Very Low | 0.01 / yr | $2K |
| Hail | Very Low | 0.11 / yr | $834 |
| Strong Wind | Very Low | 0.10 / yr | $1K |
| Ice Storm | Very Low | 0.01 / yr | $405 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Cold Wave | Very Low | 0.00 / yr | $0 |
| Drought | Very Low | 65.68 / 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
San Juan County has received 6 federal disaster declarations since 1970, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Biological (2), Flood (2), Coastal Storm (1).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2005 | Coastal Storm | Hurricane Katrina Evacuation |
| June 2002 | Fire | Wildfires |
| July 1973 | Flood | Flooding & Landslides |
| September 1970 | Flood | Heavy Rains & Flooding |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for San Juan County?
San Juan County has a composite FEMA National Risk Index score of 10.7 out of 100, placing it in the Very Low category and the 11th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in San Juan County?
The three highest-rated hazards are Avalanche (Very High, $6M EAL), Landslide (Low, $5K EAL), Lightning (Low, $196K EAL). These account for most of the county's expected annual losses.
How does San Juan County compare to other Colorado counties?
San Juan County ranks #52 of 64 Colorado counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has San Juan County had?
FEMA records 6 federal disaster declarations for San Juan County since 1970, most often 2 for biological events and 2 for flood events. The most recent was Covid-19 Pandemic, declared in March 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. San Juan County's $7M EAL is a statistical average, not a guarantee for any specific year or address.