Solano County, California Natural Disaster Risk
FEMA National Risk Index assessment · CA
HighComposite Risk Score
National percentile: 97th
Solano County faces high composite natural disaster risk (NRI Risk Index score 97.0, 97th national percentile), driven primarily by drought and earthquake exposure. Expected annual loss across all 18 hazard types is $292M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Solano County is high, with a National Risk Index score of 97.0 out of 100 — placing it in the 97th 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 drought (extended dry periods that stress water supplies and agriculture) at High risk — $12M in expected annual loss and about 67.40 events per year; earthquake (ground shaking from sudden movement along geologic faults) at High risk — $128M in expected annual loss and about 0.13 events per year; and landslide (downhill movement of rock, soil, and debris on unstable slopes) at High risk — $894K in expected annual loss and about 8.50 events per year. Across all hazards, FEMA estimates $292M in expected annual loss for a population of 453K.
Beyond physical exposure, Solano 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: Solano County has received 30 federal disaster declarations since 1964, including 8 for flood events and 7 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, Solano County ranks #20 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | High | 67.40 / yr | $12M |
| Earthquake | High | 0.13 / yr | $128M |
| Landslide | High | 8.50 / yr | $894K |
| Riverine Flood | High | 0.79 / yr | $141M |
| Wildfire | Medium | 0.01 / yr | $3M |
| Coastal Flood | High | 2.63 / yr | $4M |
| Heat Wave | Low | 6.50 / yr | $1M |
| Volcanic Activity | Very Low | 0.00 / yr | $108 |
| Lightning | Medium | 5.22 / yr | $380K |
| Tornado | Low | 0.12 / yr | $722K |
| Hail | Very Low | 0.05 / yr | $71K |
| Strong Wind | Low | 0.04 / yr | $172K |
| Tsunami | Very Low | 0.34 / yr | $101K |
| Winter Weather | Very Low | 0.10 / yr | $3K |
| Avalanche | Very Low | 0.01 / 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
Solano County has received 30 federal disaster declarations since 1964, most recently Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides in April 2023. Most frequent causes: Flood (8), Severe Storm (7), Fire (7).
| 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 |
| August 2020 | Fire | Wildfires |
| August 2020 | Fire | Lnu Lightning Fire Complex |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| October 2017 | Fire | Wildfires |
| October 2017 | Fire | Atlas Fire |
| April 2017 | Flood | Severe Winter Storms, Flooding, and Mudslides |
Showing the 10 most recent of 30 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Solano County?
Solano County has a composite FEMA National Risk Index score of 97.0 out of 100, placing it in the High category and the 97th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Solano County?
The three highest-rated hazards are Drought (High, $12M EAL), Earthquake (High, $128M EAL), Landslide (High, $894K EAL). These account for most of the county's expected annual losses.
How does Solano County compare to other California counties?
Solano County ranks #20 of 58 California counties for overall natural disaster risk, with a high rating.
How many federally declared disasters has Solano County had?
FEMA records 30 federal disaster declarations for Solano County since 1964, most often 8 for flood events and 7 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. Solano County's $292M EAL is a statistical average, not a guarantee for any specific year or address.