Sonoma County
California — Natural Disaster Risk Assessment
HighComposite Risk Score
National percentile: 99th
Sonoma County faces high composite natural disaster risk (NRI Risk Index score 99.1, 99th national percentile), driven primarily by landslide and earthquake exposure. Expected annual loss across all 18 hazard types is $605M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Landslide | High | 67.44 / yr | $5M |
| Earthquake | High | 0.12 / yr | $284M |
| Drought | High | 33.50 / yr | $14M |
| Riverine Flood | High | 2.54 / yr | $280M |
| Wildfire | High | 0.00 / yr | $17M |
| Heat Wave | Medium | 7.00 / yr | $3M |
| Volcanic Activity | Low | 0.00 / yr | $3K |
| Coastal Flood | Medium | 3.42 / yr | $1M |
| Lightning | Medium | 3.73 / yr | $341K |
| Tsunami | Very Low | 0.34 / yr | $244K |
| Hail | Very Low | 0.02 / yr | $60K |
| Tornado | Very Low | 0.08 / yr | $163K |
| Strong Wind | Very Low | 0.02 / yr | $119K |
| Avalanche | Very Low | 0.01 / yr | $10 |
| Winter Weather | Very Low | 0.74 / yr | $6K |
| Cold Wave | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Ice Storm | Very Low | 0.00 / yr | $0 |
Frequently Asked Questions
What is the overall natural disaster risk for Sonoma County?
Sonoma County has a composite FEMA National Risk Index score of 99.1 out of 100, placing it in the High category and the 99th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Sonoma County?
The three highest-rated hazards are Landslide (High, $5M EAL), Earthquake (High, $284M EAL), Drought (High, $14M EAL). These account for most of the county's expected annual losses.
How does Sonoma County compare to other California counties?
Sonoma County ranks #13 of 58 California counties for overall natural disaster risk, with a high 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. Sonoma County's $605M EAL is a statistical average, not a guarantee for any specific year or address.