Marin County, California Natural Disaster Risk
FEMA National Risk Index assessment · CA
HighComposite Risk Score
National percentile: 96th
Marin County faces high composite natural disaster risk (NRI Risk Index score 96.4, 96th national percentile), driven primarily by landslide and earthquake exposure. Expected annual loss across all 18 hazard types is $259M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Marin County is high, with a National Risk Index score of 96.4 out of 100 — placing it in the 96th national percentile and in the upper tier of natural-disaster risk nationally. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in landslide (downhill movement of rock, soil, and debris on unstable slopes) at High risk — $2M in expected annual loss and about 12.05 events per year; earthquake (ground shaking from sudden movement along geologic faults) at High risk — $110M in expected annual loss and about 0.10 events per year; and coastal flood (seawater inundation from storm surge, high tides, and rising sea levels) at Very High risk — $20M in expected annual loss and about 1.62 events per year. Across all hazards, FEMA estimates $259M in expected annual loss for a population of 262K.
Beyond physical exposure, Marin County has a low social vulnerability rating (how susceptible the population is to harm) and a very high community resilience rating (its capacity to prepare for and recover from disasters). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
The county's disaster history tells the same story: Marin County has received 26 federal disaster declarations since 1964, including 10 for severe storm events and 9 for flood events. The most recent was Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides (severe storm), declared in April 2023.
Among 58 California counties, Marin County ranks #27 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | High | 12.05 / yr | $2M |
| Earthquake | High | 0.10 / yr | $110M |
| Coastal Flood | Very High | 1.62 / yr | $20M |
| Riverine Flood | High | 2.11 / yr | $116M |
| Wildfire | Medium | 0.00 / yr | $4M |
| Heat Wave | Low | 4.53 / yr | $1M |
| Tsunami | Medium | 0.34 / yr | $6M |
| Volcanic Activity | Very Low | 0.00 / yr | $56 |
| Drought | Low | 28.97 / yr | $183K |
| Lightning | Low | 3.29 / yr | $146K |
| Tornado | Very Low | 0.05 / yr | $242K |
| Strong Wind | Very Low | 0.03 / yr | $96K |
| Winter Weather | Very Low | 0.39 / yr | $3K |
| Hail | Very Low | 0.02 / yr | $9K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Cold Wave | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Ice Storm | Very Low | 0.00 / yr | $0 |
Disaster History
Marin County has received 26 federal disaster declarations since 1964, most recently Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides in April 2023. Most frequent causes: Severe Storm (10), Flood (9), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| April 2023 | Severe Storm | Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides |
| January 2023 | Flood | Severe Winter Storms, Flooding, Landslides, and Mudslides |
| January 2023 | Flood | Severe Winter Storms, Flooding, and Mudslides |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| May 2019 | Severe Storm | Severe Winter Storms, Flooding, Landslides, and Mudslides |
| May 2019 | Severe Storm | Severe Winter Storms, Flooding, Landslides, and Mudslides |
| April 2017 | Flood | Severe Winter Storms, Flooding, and Mudslides |
| February 2017 | Severe Storm | Severe Winter Storms, Flooding, and Mudslides |
| June 2006 | Severe Storm | Severe Storms, Flooding, Landslides, and Mudslides |
Showing the 10 most recent of 26 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Marin County?
Marin County has a composite FEMA National Risk Index score of 96.4 out of 100, placing it in the High category and the 96th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Marin County?
The three highest-rated hazards are Landslide (High, $2M EAL), Earthquake (High, $110M EAL), Coastal Flood (Very High, $20M EAL). These account for most of the county's expected annual losses.
How does Marin County compare to other California counties?
Marin County ranks #27 of 58 California counties for overall natural disaster risk, with a high rating.
How many federally declared disasters has Marin County had?
FEMA records 26 federal disaster declarations for Marin County since 1964, most often 10 for severe storm events and 9 for flood events. The most recent was Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides, declared in April 2023.
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. Marin County's $259M EAL is a statistical average, not a guarantee for any specific year or address.