Monday's 5.2 magnitude temblor marked another success for California's early earthquake warning system, with users in some areas saying they got notifications on their phone before they felt shaking.

A moderately strong, 5.2-magnitude earthquake struck in Southern California on Monday, according to the United States Geological Survey. The temblor happened at 10:08 a.m. Pacific time about 2 miles south of Julian, Calif., data from the agency shows. U.S.G.S. data earlier reported that the magnitude was 6.

A magnitude 5.2 earthquake jolted southern California Monday morning near San Diego felt as far away as Mexico, according to the U.S. Geological Survey.