The quake struck at 11:18 a.m. about two miles west of Concord at a depth of about four miles.
The earthquake caused a 10 to 15 residual delay of the Bay Area Rapid Transit.
“Earlier, an earthquake had been felt within the area serviced by BART. Trains were running at reduced speeds completing track inspections,” SF BART tweeted.
There are no immediate reports of damage or injuries.
NewsNation affiliate KRON contributed to this report.