FEMA rates relative earthquake risk for Contra Costa County as very high and reports modeled annual probability of 0.97% per year for the area.
FEMA summary
FEMA's profile for Contra Costa County reports modeled annual probability of 0.97% per year for earthquake. FEMA's relative risk rating for the area is very high; the annualized frequency is a separate measure.
Hazard metrics cover FEMA county-equivalent geographies rather than individual addresses or parcels. Use local or state hazard maps before making a property, insurance, retrofit, or evacuation decision.
Select a hazard to inspect FEMA's figures for Contra Costa County.
Earthquake
FEMA combines its area-wide loss estimate and community data in this relative rating. Event frequency appears separately below.
Relative FEMA score
99.8/100
FEMA models earthquake annualized frequency as the probability of a qualifying occurrence in a given year across the FEMA geography shown.
The area loss estimate combines FEMA's modeled losses to buildings, population, and agriculture across Contra Costa County. It is not an estimate for a home or address.
City risk summary
For San Ramon, FEMA rates earthquake risk for Contra Costa County as very high, with a relative score of 99.8/100. The next highest relative scores are drought at 99.3/100 and riverine flooding at 96.2/100.
Using FEMA data for Contra Costa County, San Ramon is tied #64 among 111 covered California entries for earthquake risk; 4 entries share that score. Livermore is about 11 straight-line miles from the San Ramon map point; its FEMA figures cover Alameda County.
For homeowners and movers
Preparedness actions
Living in San Ramon? Learn how to handle water storage, sanitation, and security in a small space.
The map shows San Ramon. All FEMA figures on this page cover Contra Costa County.
The FEMA figures cover Contra Costa County. Address-level conditions require local maps, building records, and property details.
FEMA rates relative earthquake risk for Contra Costa County as very high. Its modeled annual probability is 0.97% per year. Damage at a specific address also depends on the building, soil, elevation, and exact hazard zone.
Among 111 California cities covered by this directory, San Ramon is Tied #64 for relative earthquake risk based on FEMA's score for Contra Costa County. 4 covered cities share this rank because they use the same FEMA geography. Homes within San Ramon can have different soil, elevation, construction, and hazard-zone conditions.
In FEMA's data for Contra Costa County, the highest relative ratings are Earthquake (Very High), Drought (Relatively High), and Riverine Flooding (Relatively High). FEMA uses estimated losses and community data along with event frequency when assigning these ratings.
The hazard numbers cover Contra Costa County. For an individual home, check local fault, flood, fire, evacuation, and building records for the exact address.
FEMA gives Contra Costa County an overall relative risk rating of very high. Conditions at a specific home depend on its hazard zones, building type, maintenance, insurance, and access to evacuation routes and emergency services.
Start with this step: Check whether your home has an unbraced cripple wall, an unbolted foundation, or an unsecured water heater; use a qualified local professional for retrofit decisions. Secure tall furniture and heavy objects that could fall where people sleep or sit. Use Ready.gov Earthquakes and local emergency guidance for a complete plan.
Distances are measured between city coordinates.
| City | Distance | Earthquake rating | Relative score |
|---|---|---|---|
| Livermore, CA | 11 mi | Very High | 99.9 |
| Hayward, CA | 12 mi | Very High | 99.9 |
| San Leandro, CA | 13 mi | Very High | 99.9 |
| Concord, CA | 15 mi | Very High | 99.8 |
| Oakland, CA | 15 mi | Very High | 99.9 |
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View productHazard metrics come from FEMA National Risk Index v1.19.0 (March 2023). City population and coordinates come from SimpleMaps US Cities Database. For current conditions, use official local maps, warnings, inspections, and professional advice.