California Earthquake Risk Map 2025: Which Cities Are Most at Risk?

California sits on the infamous San Andreas Fault and dozens of other active fault lines, making it one of the most earthquake-prone regions in the United States. But not all California cities face the same level of risk.

Highest Risk Cities in California

1. San Francisco/Oakland (Very High Risk)

The San Andreas Fault runs directly through this region. The 1906 M7.9 earthquake destroyed San Francisco, killed over 3,000 people, and caused fires that burned for three days.

Current risk assessment:

• Scientists estimate a 72% chance of a M6.7+ earthquake before 2043
• The Hayward Fault (runs under Oakland) is considered "overdue" for a major event
• Last major Hayward Fault earthquake was in 1868
• Dense urban population increases casualty risk
• Older buildings in downtown areas vulnerable

2. Los Angeles (Very High Risk)

Surrounded by multiple active faults including the San Andreas, Newport-Inglewood, Puente Hills, and dozens of smaller faults. The region experiences thousands of small earthquakes annually.

Major fault zones:

• San Andreas: Capable of M7.8+ earthquake
• Newport-Inglewood: Runs through densely populated areas
• Puente Hills: Blind thrust fault under LA (discovered 1999)
• Hollywood Fault: Directly under Hollywood

A M7.8 earthquake on the southern San Andreas could:

• Affect 20+ million people
• Cause $200+ billion in damage
• Sever major highways and water systems
• Trigger thousands of aftershocks

3. Riverside/San Bernardino (Very High Risk)

Located near the San Jacinto Fault and San Andreas Fault intersection. The area experiences frequent seismic activity and is in the direct path of "The Big One."

• San Jacinto Fault is California's most active fault
• M6.0+ earthquakes every 100-150 years
• Last major event: 1918 M6.8
• Rapid population growth increases vulnerability

4. Eureka/Humboldt County (Very High Risk)

Near the Cascadia Subduction Zone, which could produce a M9.0+ megaquake. This is California's hidden earthquake threat that most people don't know about.

The Cascadia threat:

• Last major event: January 26, 1700 (M9.0 estimated)
• Earthquake cycle: 300-600 years
• We're 325 years into the current cycle
• Would trigger massive tsunami
• Could shake for 3-5 minutes

5. Palm Springs/Coachella Valley (High Risk)

Sits directly on the San Andreas Fault. The fault is "locked" here, meaning pressure is building with no release through small earthquakes.

• Surface trace of San Andreas clearly visible
• Last major rupture: ~1690 (335 years ago)
• Desert sand amplifies shaking
• Tourist population creates evacuation challenges

Moderate Risk Cities

Sacramento

Further from major faults but can still experience strong shaking from distant large quakes. Soft sediment in the Central Valley amplifies shaking.

• Could experience M6.0+ shaking from Bay Area earthquake
• State capital means government disruption risk
• Older buildings not built to modern codes

Fresno

Central Valley location means softer sediment that amplifies shaking. While not on a major fault, strong earthquakes elsewhere in California would be felt strongly here.

Lower Risk Cities

San Diego

While still in California, San Diego is further from major faults and experiences less frequent large earthquakes. However, the Rose Canyon Fault runs offshore and through parts of the city.

• Last major local earthquake: 1862
• Rose Canyon Fault capable of M6.9
• Would still feel "The Big One" but less intensely
• Tsunami risk from offshore earthquakes

What Makes California So Earthquake-Prone?

California straddles the boundary between the Pacific and North American tectonic plates. The Pacific Plate moves northwest at about 2 inches per year, causing friction along faults like the San Andreas.

This accumulated stress is released as earthquakes. The longer a fault section goes without a major earthquake, the more stress builds up, increasing the likelihood of a large event.

Historical California Earthquakes

• 1906 San Francisco (M7.9): 3,000+ deaths, city destroyed
• 1989 Loma Prieta (M6.9): 63 deaths, Bay Bridge collapsed
• 1994 Northridge (M6.7): 57 deaths, $20+ billion damage
• 2019 Ridgecrest (M7.1): Minimal damage due to remote location

How to Prepare

If you live in a high-risk California city:

• Secure your home: Strap water heaters, secure bookcases, install cabinet latches
• Create emergency kit: Water, food, first aid, flashlight, radio
• Know safe spots: Under desks, doorways, away from windows
• Practice drills: "Drop, Cover, Hold On" with your family
• Consider insurance: Standard homeowners insurance doesn't cover earthquakes
• Retrofit older homes: Bolt house to foundation, brace cripple walls

Building Codes Save Lives

California has some of the strictest building codes in the world. Buildings constructed after 1980 are generally much safer than older structures. If you're buying or renting, ask about:

• Year of construction
• Seismic retrofitting
• Building type (wood frame better than unreinforced masonry)
• Foundation bolting

The Bottom Line

Living in California means accepting earthquake risk. However, with proper preparation and modern building standards, the risk can be significantly reduced. The key is not avoiding California, but preparing for the inevitable earthquake.

Scientists can't predict when "The Big One" will strike, but they're certain it will happen eventually. The best defense is preparation, not panic.

Additional Resources

Read our earthquake preparedness FAQ for a complete checklist and safety information.