San Mateo, CA Earthquake Alert: Latest Updates & Risk Info!

Carey Jast 13 May 2025

Are you prepared for the next seismic event? San Mateo, California, stands as a region of high earthquake risk, a fact underscored by a staggering history of over 5,528 recorded earthquakes since 1931.

The ground beneath San Mateo, California, is far from still. The United States Geological Survey (USGS) database presents a sobering statistic: there's a 99.06% probability of a major earthquake striking within 50 kilometers of San Mateo within the coming five decades. This isn't just a theoretical possibility; it's a palpable threat, a constant companion for those who call the area home. The region's seismic activity is a documented reality, a consequence of its location within a complex network of fault lines, most notably the infamous San Andreas Fault.

Recent events serve as a stark reminder of this enduring risk. Just a short time ago, on Friday, October 27th, 2023, at 6:38 pm local time, an earthquake with a preliminary magnitude of 3.9 rumbled just 5 miles northwest of San Mateo. The tremor, originating at a shallow depth of 8.1 miles, further emphasized the area's vulnerability. This event, swiftly reported by the USGS, was a localized instance in a broader pattern of seismic activity that regularly punctuates the landscape. Another event that same day, a preliminary 2.9 magnitude earthquake, struck the county at 4:55 p.m., centered just 0.6 miles east, adding to the day's seismic activity.

The beauty of San Mateo County, a tapestry of diverse communities and stunning landscapes, is interwoven with the inherent risk of earthquakes. From the shores of the bay to the rugged coastline, the hillsides and the more populated areas, all residents share the common reality of living in "earthquake country." The Loma Prieta earthquake of 1989, a magnitude 6.9 event, serves as a powerful historical lesson. Striking on October 17th, 1989, in the Santa Cruz Mountains, it claimed 62 lives and inflicted $6 billion in damages, a stark reminder of the destructive power of these natural events. The memory of this event underscores the necessity of preparation and awareness for anyone living in the San Mateo area.

The data suggests that the area experiences frequent seismic activity. Events are often reported within minutes, with the potential for aftershocks and additional tremors in the days and weeks following a major event. Understanding these risks is paramount to personal safety and community resilience.

Emergency officials within San Mateo County are actively working on methods of communication to ensure that accurate and helpful information is easily accessible to the public in the event of an earthquake or potential tsunami. These advancements are intended to help reduce misinformation and any confusion. The development and maintenance of effective communication channels is crucial for helping people through events and in ensuring that they can be made aware of risks and how to stay safe.

Seismic events are monitored around the clock in the bay area and the USGS is always assessing potential risks.

This table provides data on seismic activity in the region to further understand its potential risks.

Earthquake Category	Activity
Earthquakes in the Past 24 Hours (M1.5 or Greater)	0
Earthquakes in the Past 7 Days (M1.5 or Greater)	0
Earthquakes in the Past 30 Days (M1.5 or Greater)	3
Earthquakes in the Past 365 Days (M1.5 or Greater)	16
Earthquakes in the Past 24 Hours (M1.5 or Greater) near San Mateo)	1
Earthquakes in the Past 7 Days (M1.5 or Greater) near San Mateo)	1
Earthquakes in the Past 30 Days (M1.5 or Greater) near San Mateo)	1
Earthquakes in the Past 365 Days (M1.5 or Greater) near San Mateo)	17

The maps encompass areas in Contra Costa County, including Clayton, Concord, Pittsburg, and Walnut Creek, as well as San Mateo County communities such as Brisbane, Colma, Daly City, Half Moon Bay, Pacifica, San Bruno, and South San Francisco. These maps cover approximately 60 square miles, highlighting the breadth of the threat. The epicenter of a recent event was located in Millbrae, San Mateo County. The San Andreas Fault passes through this region, reinforcing the ongoing vigilance needed by those who live and work in the area.

The frequency of earthquakes, combined with the potential for larger events, underscores the need for continuous preparation. Understanding the risks involved in living in a seismically active area, like San Mateo County, is the first step toward effective preparedness.

The USGS provides tools and resources to stay updated on the latest seismic activity. Residents should be aware of the information and be prepared.

Another earthquake occurred in the region. On Friday, a magnitude 3.7 earthquake was reported near Daly City, San Mateo County. The seismic event was recorded at 7:02 am at a shallow depth of 5.2 miles, with the epicenter located near Daly City.

It is important to realize that the San Andreas Fault is an ever present risk to the residents of the area, and being aware of the data and potential threats is vital.

In the past 10 years, the strongest event near San Mateo took place on July 8, 2021.

When a major earthquake occurred in the Northern California area, the NWS issued a tsunami warning, which serves to underscore the potential regional impact of seismic events.

The quake hit at a shallow depth of 8.1 miles beneath the epicenter near San Mateo, San Mateo County, California, USA, early evening on Friday, October 27th, 2023, at 6:38 pm local time. A preliminary 2.9 magnitude earthquake struck san mateo county friday afternoon, according to the united states geological survey. The quake hit at 4:55 p.m. and was centered 0.6 miles east.