A magnitude 4.2 earthquake struck Fontana at 5:54 a.m. on Saturday and light shaking was felt in many parts of Orange County.
The U.S. Geological Survey reported the quake’s depth at 4.5 kilometers, or about 3 miles.
More than 2,800 people reported feeling the temblor on the USGS website, with most saying there was light shaking. No damage was initially reported.
A smaller magnitude 2.9 quake struck Brawley near the Salton Sea on Friday afternoon, according to the USGS.