Boulder County
Colorado — Natural Disaster Risk Assessment
MediumComposite Risk Score
National percentile: 91th
Boulder County faces medium composite natural disaster risk (NRI Risk Index score 90.7, 91th national percentile), driven primarily by lightning and hail exposure. Expected annual loss across all 18 hazard types is $125M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Lightning | Very High | 54.13 / yr | $6M |
| Hail | High | 5.48 / yr | $10M |
| Wildfire | High | 0.01 / yr | $16M |
| Winter Weather | High | 21.40 / yr | $1M |
| Tornado | High | 0.52 / yr | $12M |
| Riverine Flood | Medium | 0.75 / yr | $69M |
| Landslide | Medium | 0.27 / yr | $78K |
| Avalanche | High | 0.63 / yr | $2M |
| Strong Wind | High | 1.00 / yr | $2M |
| Earthquake | Low | 0.00 / yr | $2M |
| Ice Storm | Medium | 0.01 / yr | $354K |
| Cold Wave | Medium | 0.59 / yr | $3M |
| Volcanic Activity | Very Low | 0.00 / yr | $79 |
| Heat Wave | Low | 0.31 / yr | $815K |
| Drought | Low | 11.23 / yr | $79K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Frequently Asked Questions
What is the overall natural disaster risk for Boulder County?
Boulder County has a composite FEMA National Risk Index score of 90.7 out of 100, placing it in the Medium category and the 91th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Boulder County?
The three highest-rated hazards are Lightning (Very High, $6M EAL), Hail (High, $10M EAL), Wildfire (High, $16M EAL). These account for most of the county's expected annual losses.
How does Boulder County compare to other Colorado counties?
Boulder County ranks #6 of 64 Colorado counties for overall natural disaster risk, with a medium rating.
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. Boulder County's $125M EAL is a statistical average, not a guarantee for any specific year or address.