On December 4, 2025, millions of cell phones in California and Nevada buzzed with ShakeAlert warnings of a magnitude 5.9 earthquake near Dayton, Nevada. Emergency teams mobilized, 911 lines overloaded,

SAN RAMON — A cluster of earthquakes struck the San Ramon area Friday night, continuing a pattern of seismic activity in recent weeks, according to the U.S. Geological Survey. Things kicked off at 7:41 p.m. with a magnitude 2.5 centered 3.1 miles southeast of the city.

SAN BENITO COUNTY, CA - A 3.5 magnitude quake was reported near Ridgemark on Sunday around midday, according to the U.S. Geological Survey.

“On December 4, 2025, the ShakeAlert EEW system released an incorrect alert for a magnitude 5.9 earthquake near Reno and Carson City, Nevada,” the statement read. “The event did not occur, and has been deleted from USGS websites and data feeds. The USGS is working to understand the cause of the false alert.”

A series of earthquakes rattled the San Ramon area Friday night, with the largest being a preliminary magnitude 4.0, according to the U.S. Geological Survey.

The United States Geological Survey put out a false alarm for a 5.9 earthquake east of Dayton, Nevada, on Thursday morning.

Several small earthquakes struck in the East Bay near San Ramon on Friday evening, according to data from the U.S. Geological Survey. The largest measured as a magnitude 4.0 quake.

Several earthquakes, the largest measured at magnitude-3.3, were reported Thursday morning in Ventura County. The earthquakes were centered near Fillmore, about 25 miles northeast of Ventura. Shaking was reported in Fillmore, Moorpark, Ventura and Santa Paula.

In California's East Bay, a recent swarm of small earthquakes has pushed long-standing seismic risks back into public view. Since early November 2025, at least 90 minor quakes have been recorded around San Ramon,