A minor earthquake struck Contra Costa County Monday afternoon, with shaking felt in parts of the East Bay, officials announced.

According to the U.S. Geological Survey, a magnitude 3.5 quake struck at 3 p.m. The epicenter was located about 5 miles east of Clayton and 6 miles southeast of Pittsburg, at a depth of about 4 miles.

Visitors to the USGS website from communities throughout inland Contra Costa County reported light shaking, particularly in the communities of Antioch, Pittsburg, Clayton, Concord and Oakley. Shaking was reportedly felt as far as Sacramento County and Santa Clara County.

Map of earthquake that struck east of Clayton in Contra Costa County on Sep. 15, 2025. U.S. Geological Survey

There are no immediate reports of damage or injuries.

See Full Page