3.8 Magnitude Earthquake Strikes San Ramon Area on Sunday Morning

SAN RAMON, Calif. (KGO) — A 3.8-magnitude earthquake struck near San Ramon at 9:38 a.m. Pacific time on Sunday, November 9, 2025, according to the United States Geological Survey (USGS). The quake’s epicenter was located about 2 miles southeast of San Ramon.

Initial reports from the USGS had indicated a magnitude of 3.7, but this was later upgraded. Seismologists are reviewing the data and may make further adjustments.

Following the first quake, several smaller tremors were recorded in quick succession throughout the morning. These included a 3.7 quake at 9:39 a.m., a 3.0 jolt at 9:41 a.m., and a 2.9 quake also at 9:41 a.m. More aftershocks continued into the late morning, with a notable 2.5 magnitude quake registered at 10:18 a.m.

Approximately 1,600 residents across the East Bay and San Francisco reported feeling the initial quake, yet local authorities confirmed there were no immediate reports of damage or injuries.

The recent seismic activity is part of a swarm along the Calaveras fault, which has registered over 40 earthquakes since November 9. The most significant, at 3.8 magnitude, struck at a depth of 9.2 kilometers (5.7 miles). The swarm is characterized by these minor tremors, which often do not indicate an imminent larger earthquake.

The Calaveras fault, a crucial part of the San Andreas fault system, has a history of producing significant earthquakes. Geological studies suggest it could generate larger quakes in the future. The USGS and California Geological Survey are closely monitoring the situation.

As of November 10, there had been no signs of significant risk or unusual behavior along the fault. Smaller aftershocks are expected to continue.