Natural disaster risk in California, by county
All 58 counties in California, ranked by FEMA's National Risk Index composite risk score, with each one's highest-rated hazard. Other states
At a glance
Highest overall risk: Los Angeles County (very high, score 100.0). Lowest: Alpine County (very low, score 10.6).
Top hazards in California
| Hazard | Counties rated relatively high or very high | Average score |
|---|---|---|
| Inland (riverine) flooding | 33 of 58 | 85.2 |
| Drought | 32 of 58 | 83.3 |
| Wildfire | 30 of 58 | 93.7 |
| Landslide | 29 of 58 | 88.5 |
| Earthquake | 27 of 58 | 92.6 |
All counties, highest risk first
| # | County | Overall risk | Highest-rated hazard |
|---|---|---|---|
| 1 | Los Angeles County | Very high 100 | Earthquake (very high) |
| 2 | Riverside County | Very high 99.9 | Earthquake (very high) |
| 3 | Alameda County | Very high 99.8 | Earthquake (very high) |
| 4 | Orange County | Very high 99.8 | Earthquake (very high) |
| 5 | San Bernardino County | Very high 99.8 | Earthquake (very high) |
| 6 | San Diego County | Very high 99.7 | Wildfire (very high) |
| 7 | Santa Clara County | Very high 99.7 | Earthquake (very high) |
| 8 | Contra Costa County | Very high 99.5 | Inland (riverine) flooding (very high) |
| 9 | San Francisco County | Very high 99.5 | Earthquake (very high) |
| 10 | Ventura County | Relatively high 99.4 | Inland (riverine) flooding (very high) |
| 11 | Fresno County | Relatively high 99.3 | Drought (very high) |
| 12 | San Mateo County | Relatively high 99.2 | Earthquake (relatively high) |
| 13 | Sonoma County | Relatively high 99.1 | Drought (relatively high) |
| 14 | Santa Barbara County | Relatively high 99 | Landslide (very high) |
| 15 | Kern County | Relatively high 98.9 | Earthquake (relatively high) |
| 16 | Monterey County | Relatively high 98.7 | Drought (very high) |
| 17 | San Joaquin County | Relatively high 98.6 | Drought (very high) |
| 18 | Sacramento County | Relatively high 98.1 | Drought (relatively high) |
| 19 | Santa Cruz County | Relatively high 97.8 | Drought (relatively high) |
| 20 | Solano County | Relatively high 97 | Drought (relatively high) |
| 21 | Tulare County | Relatively high 97 | Heat wave (relatively high) |
| 22 | Merced County | Relatively high 96.9 | Drought (very high) |
| 23 | Stanislaus County | Relatively high 96.9 | Drought (very high) |
| 24 | Humboldt County | Relatively high 96.8 | Landslide (relatively high) |
| 25 | Imperial County | Relatively high 96.5 | Earthquake (relatively high) |
| 26 | Madera County | Relatively high 96.4 | Drought (very high) |
| 27 | Marin County | Relatively high 96.4 | Coastal flooding (very high) |
| 28 | San Luis Obispo County | Relatively high 95.9 | Drought (very high) |
| 29 | Napa County | Relatively high 95.3 | Drought (very high) |
| 30 | Del Norte County | Relatively high 94.4 | Tsunami (very high) |
| 31 | Mendocino County | Relatively high 94.3 | Landslide (relatively high) |
| 32 | Butte County | Relatively moderate 93.9 | Drought (very high) |
| 33 | Shasta County | Relatively moderate 93.4 | Wildfire (relatively high) |
| 34 | Placer County | Relatively moderate 93.1 | Avalanche (very high) |
| 35 | Lake County | Relatively moderate 93 | Wildfire (relatively high) |
| 36 | Kings County | Relatively moderate 92.4 | Drought (very high) |
| 37 | El Dorado County | Relatively moderate 91.4 | Wildfire (relatively high) |
| 38 | Yolo County | Relatively moderate 91.4 | Drought (very high) |
| 39 | Nevada County | Relatively moderate 89.9 | Wildfire (relatively high) |
| 40 | Siskiyou County | Relatively moderate 89 | Drought (relatively high) |
| 41 | Tehama County | Relatively moderate 88.9 | Drought (relatively high) |
| 42 | Calaveras County | Relatively moderate 86.6 | Wildfire (relatively high) |
| 43 | Mariposa County | Relatively moderate 86.4 | Landslide (relatively high) |
| 44 | Plumas County | Relatively moderate 86.4 | Wildfire (relatively high) |
| 45 | San Benito County | Relatively moderate 85.2 | Drought (relatively high) |
| 46 | Tuolumne County | Relatively moderate 85.2 | Wildfire (relatively high) |
| 47 | Sutter County | Relatively moderate 83.7 | Drought (very high) |
| 48 | Colusa County | Relatively moderate 81.1 | Drought (very high) |
| 49 | Yuba County | Relatively low 80.9 | Drought (relatively high) |
| 50 | Trinity County | Relatively low 79.5 | Landslide (relatively high) |
| 51 | Inyo County | Relatively low 79.3 | Avalanche (very high) |
| 52 | Amador County | Relatively low 79.2 | Drought (relatively high) |
| 53 | Glenn County | Relatively low 74.4 | Drought (relatively high) |
| 54 | Lassen County | Relatively low 73.1 | Wildfire (relatively moderate) |
| 55 | Mono County | Relatively low 46.5 | Avalanche (relatively high) |
| 56 | Modoc County | Very low 39.7 | Drought (relatively high) |
| 57 | Sierra County | Very low 31.5 | Wildfire (relatively moderate) |
| 58 | Alpine County | Very low 10.6 | Avalanche (relatively high) |
How to read these ratings
- Ratings run in five steps: very low, relatively low, relatively moderate, relatively high and very high. They compare a county with every other US county; they are not a measure of danger on their own.
- Scores run from 0 to 100 and are national percentiles. The bar shows the score: a score of 80 means a higher value than 80% of US counties.
- Overall risk combines the expected annual loss with social vulnerability and community resilience.
- Expected annual loss is the average yearly loss to buildings, people and agriculture the model expects from all 18 hazards.
- Social vulnerability describes how hard it may be for people to prepare for and recover from a disaster. Higher is worse.
- Community resilience describes a community's ability to prepare, adapt and recover. Higher is better.
- "Not applicable" means FEMA does not model that hazard there (for example, hurricanes far inland).
About this data
Source: FEMA National Risk Index, version 1.20, released December 2025, published by the Federal Emergency Management Agency (US public domain). About the National Risk Index. The index is a model of relative risk built from historical hazard records, what is exposed and community factors. It is not a forecast, it does not describe any single property, and it is not insurance or financial advice. For decisions about a specific address, check FEMA's flood maps and your local emergency management office.
Questions
Which county in California has the highest natural disaster risk?
Los Angeles County has the highest composite risk score in California in FEMA's National Risk Index: 100.0, rated very high.
Which county in California has the lowest natural disaster risk?
Alpine County has the lowest composite risk score in California: 10.6, rated very low. A low score means lower modelled risk compared with other US counties, not no risk.
What natural disasters is California most at risk from?
Across California, the hazards rated highest in the most counties are inland (riverine) flooding, drought, wildfire, according to FEMA's National Risk Index. Each county page lists all 18 hazards.
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