Napa County, California Natural Disaster Risk
FEMA National Risk Index assessment · CA
HighComposite Risk Score
National percentile: 95th
Napa County faces high composite natural disaster risk (NRI Risk Index score 95.3, 95th national percentile), driven primarily by drought and landslide exposure. Expected annual loss across all 18 hazard types is $186M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Napa County at high composite risk, with a National Risk Index score of 95.3 out of 100 — placing it in the 95th 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 drought (extended dry periods that stress water supplies and agriculture) at Very High risk — $21M in expected annual loss and about 60.05 events per year; landslide (downhill movement of rock, soil, and debris on unstable slopes) at High risk — $1M in expected annual loss and about 41.62 events per year; and earthquake (ground shaking from sudden movement along geologic faults) at High risk — $67M in expected annual loss and about 0.12 events per year. Across all hazards, FEMA estimates $186M in expected annual loss for a population of 138K.
Beyond physical exposure, Napa County has a low social vulnerability rating (how susceptible the population is to harm) and a 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.
History supports the rating: Napa County has received 39 federal disaster declarations since 1964, including 13 for fire events and 10 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, Napa County ranks #29 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | Very High | 60.05 / yr | $21M |
| Landslide | High | 41.62 / yr | $1M |
| Earthquake | High | 0.12 / yr | $67M |
| Wildfire | Medium | 0.00 / yr | $5M |
| Riverine Flood | High | 1.11 / yr | $90M |
| Coastal Flood | Medium | 3.61 / yr | $987K |
| Heat Wave | Low | 7.65 / yr | $794K |
| Volcanic Activity | Very Low | 0.00 / yr | $33 |
| Lightning | Low | 4.22 / yr | $110K |
| Tornado | Very Low | 0.09 / yr | $211K |
| Avalanche | Very Low | 0.01 / yr | $7 |
| Hail | Very Low | 0.04 / yr | $25K |
| Strong Wind | Very Low | 0.03 / yr | $61K |
| Winter Weather | Very Low | 1.14 / yr | $3K |
| Tsunami | Very Low | 0.33 / yr | $3K |
| 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
Napa County has received 39 federal disaster declarations since 1964, most recently Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides in April 2023. Most frequent causes: Fire (13), Severe Storm (10), Flood (8).
| 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 |
| September 2020 | Fire | Glass Fire |
| August 2020 | Fire | Wildfires |
| August 2020 | Fire | Lnu Lightning Fire Complex |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
Showing the 10 most recent of 39 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Napa County?
Napa County has a composite FEMA National Risk Index score of 95.3 out of 100, placing it in the High category and the 95th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Napa County?
The three highest-rated hazards are Drought (Very High, $21M EAL), Landslide (High, $1M EAL), Earthquake (High, $67M EAL). These account for most of the county's expected annual losses.
How does Napa County compare to other California counties?
Napa County ranks #29 of 58 California counties for overall natural disaster risk, with a high rating.
How many federally declared disasters has Napa County had?
FEMA records 39 federal disaster declarations for Napa County since 1964, most often 13 for fire events and 10 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. Napa County's $186M EAL is a statistical average, not a guarantee for any specific year or address.