The temblor struck just after 8 p.m. about three miles west of Glen Ellen in Sonoma County and 42 miles northwest of San Francisco near the Rodgers Creek Fault, the U.S. Geological Survey said. It was followed by a magnitude 2.0 aftershock about an hour later.
There were no initial reports of serious injuries or damage, according to a Sonoma County Sheriff's dispatcher. But several businesses and residents near the epicenter said Wednesday's quake sent some items tumbling to the floor.
At a Big-O Tires store in Rohnert Park, about 6 miles east of the epicenter, a fire extinguisher fell from the wall and onto a water pipe, causing some minor flooding.
Some pictures in the Benziger Family Winery gift shop in Glen Ellen fell from the walls, but the quake was just a "typical California" occurrence, said Brian Catlett, Benziger's assistant tasting room manager.
"Some pictures fell off the wall, wine shifted a little bit — nothing major," Catlett said.
The earthquake was widely felt as far north as Cloverdale and more than 80 miles to the south in San Jose, according to the USGS.
Steve Walter, a USGS seismologist in Menlo Park, said it was fortunate the quake did not actually occur on the Rodgers Creek Fault, the northern extension of the dangerous Hayward Fault, which many say is due for a major rupture.
"Rodgers Creek is capable of a large earthquake ... a 6.7 or larger," Walter said.