Late Monday night, at approximately 10:23 p.m., a 5.2-magnitude earthquake struck near Julian, a small mountain town located in San Diego County, California. The seismic event sent tremors rippling across a wide swath of Southern California, rattling homes and nerves from San Diego all the way up to Los Angeles—about 120 miles from the epicenter. Though the quake was classified as moderate in magnitude, its impact was broadly felt, with reports of shaking coming in from multiple counties and cities, including Riverside, Orange, and even portions of San Bernardino.
According to preliminary data released by the United States Geological Survey (USGS), the earthquake occurred at a depth of approximately 10 kilometers (6.2 miles) beneath the Earth’s surface—shallow enough to produce noticeable surface-level shaking. Julian, a region known more for its apple orchards and quiet mountain charm than seismic activity, rarely experiences quakes of this size. Monday night’s event was therefore met with surprise by many residents, who reported being abruptly awakened by the trembling.
Despite the intensity of the shaking, authorities, including the San Diego County Sheriff’s Department and local emergency management offices, confirmed that there were no immediate reports of injuries, fatalities, or significant property damage. Power remained on in most areas, and no major infrastructure was compromised. Several residents, however, did report items falling off shelves, minor structural creaks, and temporary internet or cellular disruptions.
In a relatively rare and encouraging development, a number of people in the region received early earthquake warning alerts on their mobile devices just seconds before the tremors began. California’s early warning system, developed in partnership with USGS and state agencies, is designed to detect the initial seismic waves—known as P-waves—that travel faster than the more destructive S-waves that follow. In this instance, some users were alerted roughly five seconds ahead of the shaking, offering a brief but potentially crucial moment to take cover or prepare. While five seconds may not sound like much, for those near the epicenter or in vulnerable settings (such as schools, hospitals, or crowded venues), it can make a meaningful difference.
The earthquake serves as a stark reminder of California’s seismic reality. Situated along the Pacific Ring of Fire, the state lies near several major fault lines, including the infamous San Andreas Fault. While this particular quake was not directly on the San Andreas system, its occurrence reinforces the ongoing need for preparedness in a region where earthquakes are not a question of “if,” but “when.”
Authorities, including seismologists at Caltech and the USGS, continue to monitor the region closely for aftershocks, which are common following quakes of this magnitude. Residents are being urged to remain cautious in the coming hours and days, and to revisit safety protocols—such as having an emergency kit, securing heavy furniture, and knowing where to “Drop, Cover, and Hold On” during seismic activity.
Many Southern Californians took to social media to share their experiences. Posts ranged from humorous quips about coffee spilling to expressions of fear and anxiety, particularly from those new to earthquake territory. “It felt like someone shook the whole building for a solid five seconds,” wrote one user from downtown San Diego. Another in Orange County described it as “a hard jolt, followed by a rolling motion, like being on a boat.” These varied personal accounts highlight how differently a single quake can be experienced depending on distance, local soil conditions, and building structure.
Though this event did not result in disaster, experts view it as an important opportunity to test emergency systems and raise public awareness. “Every earthquake, big or small, is a reminder to stay prepared,” said Dr. Lucy Hammond, a geophysicist with the California Earthquake Authority. “It’s not about living in fear—it’s about building resilience.”
As life returns to normal for most in the region, emergency officials are encouraging residents to report any damages they may have noticed and to stay informed through reliable sources such as the USGS Earthquake Map and local emergency alerts. Earthquakes often happen with little or no warning, and staying proactive can be key to minimizing risk.
While Southern California is no stranger to seismic activity, each quake—like Monday night’s—serves as a humbling reminder of nature’s unpredictable power, and of the importance of community readiness and technological advancements in keeping people safe.