3.5-Magnitude Quake Strikes Near Clayton in East Bay

Clayton, Calif. - A magnitude 3.5 earthquake shook the East Bay early Monday afternoon, rattling homes and offices but causing no reported injuries or damage.

A Swift Temblor With Minimal Impact

At 3:00 p.m. local time on September 15, the U.S. Geological Survey recorded a 3.5-magnitude quake centered just 2 miles south of Clayton at a shallow depth of 4 miles, sending light tremors across the northern East Bay.

What Happened

• Epicenter: 2 miles south of Clayton, Contra Costa County
• Magnitude: 3.5
• Depth: 4 miles
• Time: 3:00 p.m. PDT

Where It Was Felt

Residents from Antioch to Danville reported light shaking, rattling windows and prompting brief evacuations of downtown offices. Seismologists say quakes under magnitude 4.0 rarely cause structural harm.

Why It Matters

Small temblors like Monday’s remind Bay Area communities of the region’s active fault lines and the importance of earthquake preparedness-even when quakes cause minimal disruption. Emergency services used the event to review readiness protocols.

Local Response

• No injuries or damage reported, Contra Costa County Sheriff’s Office confirms.
• PG&E inspected local substations; no electrical outages occurred.
• Schools and businesses resumed normal operations after brief safety checks.

Residents with questions or concerns can visit the USGS “Latest Earthquakes” map online for real-time updates.