San Diego County, California Natural Disaster Risk
FEMA National Risk Index assessment · CA
Very HighComposite Risk Score
National percentile: 100th
San Diego County faces very high composite natural disaster risk (NRI Risk Index score 99.7, 100th national percentile), driven primarily by wildfire and earthquake exposure. Expected annual loss across all 18 hazard types is $1.54B.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates San Diego County at very high composite risk, with a National Risk Index score of 99.7 out of 100 — placing it in the 100th national percentile and among the most at-risk counties in the United States. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in wildfire (uncontrolled fires that spread across wildland and into communities) at Very High risk — $430M in expected annual loss and about 0.03 events per year; earthquake (ground shaking from sudden movement along geologic faults) at High risk — $426M in expected annual loss and about 0.11 events per year; and riverine flood (rivers and streams overflowing their banks after heavy rain or snowmelt) at Very High risk — $648M in expected annual loss and about 7.89 events per year. Across all hazards, FEMA estimates $1.54B in expected annual loss for a population of 3.3M.
Beyond physical exposure, San Diego County has a low social vulnerability rating (how susceptible the population is to harm) and a very low 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 Diego County has received 51 federal disaster declarations since 1965, including 28 for fire events and 12 for flood events. The most recent was Severe Storm and Flooding (flood), declared in February 2024.
Among 58 California counties, San Diego County ranks #6 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Wildfire | Very High | 0.03 / yr | $430M |
| Earthquake | High | 0.11 / yr | $426M |
| Riverine Flood | Very High | 7.89 / yr | $648M |
| Landslide | High | 177.45 / yr | $3M |
| Heat Wave | High | 10.25 / yr | $24M |
| Lightning | Medium | 11.11 / yr | $829K |
| Hail | Medium | 0.10 / yr | $825K |
| Coastal Flood | Medium | 1.65 / yr | $1M |
| Tornado | Low | 0.31 / yr | $2M |
| Drought | Low | 54.09 / yr | $299K |
| Tsunami | Low | 0.39 / yr | $2M |
| Strong Wind | Medium | 0.19 / yr | $642K |
| Winter Weather | Low | 3.67 / yr | $67K |
| Volcanic Activity | Very Low | 0.00 / yr | $3 |
| Avalanche | Very Low | 0.01 / yr | $137 |
| Hurricane | Very Low | 0.01 / yr | $1K |
| Cold Wave | Very Low | 0.00 / yr | $521 |
| Ice Storm | Very Low | 0.00 / yr | $0 |
Disaster History
San Diego County has received 51 federal disaster declarations since 1965, most recently Severe Storm and Flooding in February 2024. Most frequent causes: Fire (28), Flood (12), Severe Storm (5).
| Declared | Type | Disaster |
|---|---|---|
| February 2024 | Flood | Severe Storm and Flooding |
| January 2023 | Flood | Severe Winter Storms, Flooding, Landslides, and Mudslides |
| January 2023 | Flood | Severe Winter Storms, Flooding, and Mudslides |
| October 2020 | Fire | Wildfires |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| July 2018 | Fire | West Fire |
| January 2018 | Fire | Wildfires, Flooding, Mudflows, and Debris Flows |
| December 2017 | Fire | Wildfires |
| December 2017 | Fire | Lilac Fire |
Showing the 10 most recent of 51 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for San Diego County?
San Diego County has a composite FEMA National Risk Index score of 99.7 out of 100, placing it in the Very High category and the 100th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in San Diego County?
The three highest-rated hazards are Wildfire (Very High, $430M EAL), Earthquake (High, $426M EAL), Riverine Flood (Very High, $648M EAL). These account for most of the county's expected annual losses.
How does San Diego County compare to other California counties?
San Diego County ranks #6 of 58 California counties for overall natural disaster risk, with a very high rating.
How many federally declared disasters has San Diego County had?
FEMA records 51 federal disaster declarations for San Diego County since 1965, most often 28 for fire events and 12 for flood events. The most recent was Severe Storm and Flooding, declared in February 2024.
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 Diego County's $1.54B EAL is a statistical average, not a guarantee for any specific year or address.