The U.S. Geological Survey confirmed a 3.7 preliminary magnitude earthquake rattled the small city of Piedmont in northern California.
The USGS says the tremor occurred on Wednesday at 4:42 a.m.
The impacts of the earthquake were not immediately known. Earthquakes with a magnitude between 2.5 and 3 are the smallest tremors felt by people.
Piedmont is a city of roughly 10,000 people next to Oakland.