Tsunami Risk in California
All California counties ranked by FEMA National Risk Index tsunami score
Tsunami risk — series of ocean waves triggered by undersea earthquakes or landslides — is rated for 20 of 58 California counties in FEMA's National Risk Index. Del Norte County carries the state's highest tsunami score at 98.5, with $114M in expected annual tsunami losses.
2 California counties are rated High or Very High for tsunami, and expected annual losses from tsunami total roughly $192M statewide. The full ranking below links to each county's complete 18-hazard risk profile.
County Rankings — Tsunami
| # | County | Tsunami Score | Rating | Ann. Freq. | Ann. Loss |
|---|---|---|---|---|---|
| 1 | Del Norte County | Very High | 0.23 / yr | $114M | |
| 2 | Humboldt County | High | 0.23 / yr | $33M | |
| 3 | Santa Cruz County | Medium | 0.39 / yr | $8M | |
| 4 | San Francisco County | Medium | 0.34 / yr | $6M | |
| 5 | San Mateo County | Medium | 0.34 / yr | $7M | |
| 6 | Marin County | Medium | 0.34 / yr | $6M | |
| 7 | Los Angeles County | Low | 0.39 / yr | $3M | |
| 8 | San Luis Obispo County | Low | 0.38 / yr | $3M | |
| 9 | Alameda County | Low | 0.34 / yr | $3M | |
| 10 | Orange County | Low | 0.39 / yr | $3M | |
| 11 | San Diego County | Low | 0.39 / yr | $2M | |
| 12 | Contra Costa County | Low | 0.34 / yr | $1M | |
| 13 | Monterey County | Very Low | 0.39 / yr | $712K | |
| 14 | Ventura County | Very Low | 0.39 / yr | $790K | |
| 15 | Santa Barbara County | Very Low | 0.38 / yr | $343K | |
| 16 | Mendocino County | Very Low | 0.23 / yr | $264K | |
| 17 | Sonoma County | Very Low | 0.34 / yr | $244K | |
| 18 | Santa Clara County | Very Low | 0.34 / yr | $142K | |
| 19 | Solano County | Very Low | 0.34 / yr | $101K | |
| 20 | Napa County | Very Low | 0.33 / yr | $3K |
20 California counties with measurable tsunami risk. See the national tsunami ranking or all California counties by overall risk.
Frequently Asked Questions
Which California county has the highest tsunami risk?
Del Norte County has the highest FEMA tsunami risk score in California at 98.5 (Very High), with $114M in expected annual losses and about 0.23 events per year.
How many California counties face significant tsunami risk?
20 California counties record measurable tsunami risk in FEMA's National Risk Index; 2 of them are rated High or Very High.