A magnitude 3.1 earthquake struck near Fontana in San Bernardino County, California, on December 16, 2025, at 8:04 PM local time. The quake occurred at a shallow depth of approximately 4.2 miles (6.8 km), which often results in stronger surface shaking compared to deeper seismic events. The United States Geological Survey (USGS) reported this initial magnitude, which was later revised from 3.2 to 3.1 following further analysis.
Within minutes of the earthquake, numerous residents reported feeling the tremors. As of the latest updates, around 56 individuals have shared their experiences, with the majority of reports coming from nearby Fontana, San Bernardino, and Rancho Cucamonga. The felt reports indicated varying intensities, with most people experiencing very weak to light shaking.
The epicenter was located approximately 14 miles north of Riverside, making it geographically positioned close to densely populated areas. Cities such as Fontana, located just under 5 miles from the epicenter, recorded the most significant response, with residents describing the sensation as a brief jolt or light rumbling. Other nearby towns also felt the quake, including Rialto, San Bernardino, and Colton, indicating a broad impact area where the shaking was detectable.
Following the quake, various seismic agencies, including the European-Mediterranean Seismological Centre (EMSC) and the Incorporated Research Institutions for Seismology (IRIS), confirmed the 3.1 magnitude, reflecting a consensus among seismologists regarding the event’s characteristics.
The weather conditions at the time of the quake were clear with temperatures around 63°F (17.4°C), which could have contributed to the clarity with which residents perceived the tremors. Fortunately, there have been no immediate reports of significant damage or injury.
As California continues to experience seismic activity, it’s crucial for residents to remain prepared and informed about earthquake safety measures. This quake serves as a reminder of the natural forces at play in the region and the importance of community reporting in understanding and responding to these events.