Mendocino County, California Natural Disaster Risk
FEMA National Risk Index assessment · CA
HighComposite Risk Score
National percentile: 94th
Mendocino County faces high composite natural disaster risk (NRI Risk Index score 94.3, 94th national percentile), driven primarily by landslide and earthquake exposure. Expected annual loss across all 18 hazard types is $117M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Mendocino County carries a high composite natural disaster risk, with a National Risk Index score of 94.3 out of 100 — placing it in the 94th 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.
The county's risk is driven primarily by landslide (downhill movement of rock, soil, and debris on unstable slopes) at High risk — $2M in expected annual loss and about 94.88 events per year; earthquake (ground shaking from sudden movement along geologic faults) at High risk — $47M in expected annual loss and about 0.07 events per year; and wildfire (uncontrolled fires that spread across wildland and into communities) at High risk — $8M in expected annual loss and about 0.00 events per year. Across all hazards, FEMA estimates $117M in expected annual loss for a population of 91K.
Beyond physical exposure, Mendocino County has a high social vulnerability rating (how susceptible the population is to harm) and a low community resilience rating (its capacity to prepare for and recover from disasters). That combination — a more vulnerable population with limited resilience — can amplify the human cost of any given event.
The federal record bears this out: Mendocino County has received 33 federal disaster declarations since 1964, including 11 for flood events and 9 for severe storm 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, Mendocino County ranks #31 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | High | 94.88 / yr | $2M |
| Earthquake | High | 0.07 / yr | $47M |
| Wildfire | High | 0.00 / yr | $8M |
| Drought | High | 41.14 / yr | $3M |
| Riverine Flood | High | 0.75 / yr | $56M |
| Volcanic Activity | Very Low | 0.00 / yr | $199 |
| Coastal Flood | Low | 3.23 / yr | $196K |
| Heat Wave | Low | 4.06 / yr | $312K |
| Tsunami | Very Low | 0.23 / yr | $264K |
| Avalanche | Very Low | 0.01 / yr | $90 |
| Lightning | Low | 5.32 / yr | $79K |
| Winter Weather | Very Low | 6.77 / yr | $15K |
| Tornado | Very Low | 0.10 / yr | $54K |
| Hail | Very Low | 0.04 / yr | $17K |
| Strong Wind | Very Low | 0.00 / yr | $2K |
| 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
Mendocino County has received 33 federal disaster declarations since 1964, most recently Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides in April 2023. Most frequent causes: Flood (11), Severe Storm (9), Fire (6).
| Declared | Type | Disaster |
|---|---|---|
| April 2023 | Severe Storm | Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides |
| March 2023 | Flood | Severe Winter Storms, Flooding, Landslides, and Mudslides |
| January 2023 | Flood | Severe Winter Storms, Flooding, Landslides, and Mudslides |
| January 2023 | Flood | Severe Winter Storms, Flooding, and Mudslides |
| October 2020 | Fire | Wildfires |
| August 2020 | Fire | Wildfires |
| 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 |
Showing the 10 most recent of 33 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Mendocino County?
Mendocino County has a composite FEMA National Risk Index score of 94.3 out of 100, placing it in the High category and the 94th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Mendocino County?
The three highest-rated hazards are Landslide (High, $2M EAL), Earthquake (High, $47M EAL), Wildfire (High, $8M EAL). These account for most of the county's expected annual losses.
How does Mendocino County compare to other California counties?
Mendocino County ranks #31 of 58 California counties for overall natural disaster risk, with a high rating.
How many federally declared disasters has Mendocino County had?
FEMA records 33 federal disaster declarations for Mendocino County since 1964, most often 11 for flood events and 9 for severe storm 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. Mendocino County's $117M EAL is a statistical average, not a guarantee for any specific year or address.