California’s Bay Area Hammered By Over 30 Earthquakes, Strongest Recorded At 4.2

A swarm of earthquakes rattled the San Francisco Bay Area early Monday morning, centered around San Ramon in California, according to the U.S. Geological Survey (USGS).

The strongest tremor was a magnitude 4.2 quake that struck at 7:01 a.m. local time, with its epicenter in the San Ramon area. It came shortly after a 3.8 that took place at 6:27 a.m., which was a part of a sequence exceeding 30 events.

The USGS reported the 4.2-magnitude quake occurred at a depth of approximately 9.4 kilometers.

No injuries or significant structural damage has been reported from the activity.

Security footage captured inside a 7-Eleven store at the intersection of Kimball and Alcosta Boulevard in San Ramon shows items tumbling from shelves during an earthquake. (RELATED: Eastern US Set To Deal With Two New Rounds Of Snow, Late-Week Storm After Being Buried By Fern, Gianna)

According to the USGS, this latest burst appears to be a resumption of the ongoing earthquake swarm that has affected the San Ramon Valley — spanning between Walnut Creek and Dublin — for several weeks.

The region experienced a brief pause, with Friday marking the first quake in weeks, though dozens of events have occurred since the swarms began in Nov.

Local residents and employees shared with ABC7 Eyewitness News that the rapid succession of earthquakes came as a surprise, but they’ve grown accustomed to such clusters in the area.

A man from Dublin described being jolted awake by the shaking, adding that he’s become familiar with the recurring swarms over time.

A 4.2-magnitude earthquake rattled the San Francisco Bay Area on Monday morning amid a series of over 30 temblors in the area, the U.S. Geological Survey said. https://t.co/KFz8aY6xN1 pic.twitter.com/xbgvc7iQmp

— ABC7 Eyewitness News (@ABC7) February 2, 2026

“20-25 years ago, there was one that lasted a couple of weeks. They weren’t big, but just like this,” said the local.

The U.S. Geological Survey indicates that this recent burst of seismic activity is likely a resumption of the ongoing earthquake swarm that residents in the San Ramon Valley — stretching from Walnut Creek to Dublin — have experienced over the past several weeks.

“These earthquakes, some are going to be bigger than others, and some are going to be felt,” said USGS’s Robert DeGroot, per ABC7. “Many of them are very small. So the significance is that this particular sequence is just continuing and we know that this has happened in the past.”

DeGroot noted that the swarm could persist for months. (RELATED: Polar Vortex Extending Arctic Deep Freeze For Millions In Eastern United States Through February)

“This is not something that is necessarily significant of something bigger,” said DeGroot. “In fact, there’s a very small chance that something bigger will happen through this series of events. This is a very active area between Mount Diablo and Calaveras fault.”

Mark Armstrong, the mayor of San Ramon, reported feeling the earthquakes himself and stated that the city remains committed to ensuring both municipal operations and residents stay well-prepared for such events.

“The city is closely monitoring the situation; these earthquake swarms are not uncommon,” said Armstrong, per ABC7. “There’s experts, the scientists, are tracking all this information. San Ramon’s emergency preparedness systems are strong.”

Bay Area Rapid Transit (BART) temporarily reduced train speeds to allow for track inspections, a standard precaution taken during periods of earthquake activity.