The magnitude-5.1 earthquake at 2:41 p.m. startled Southern Californians who were already braced for the remnant of Hurricane Hilary, which had already brought hours of steady rain during the region’s driest month of the year. There were at least a dozen aftershocks of magnitude-3.0 or greater.

The earthquake was centered about four miles southeast of Ojai, about 80 miles northwest of Los Angeles.