Magnitude 3.5 earthquake shakes Southern California near Rialto and Fontana

On Tuesday (5), at 4:54 p.m. local time, a magnitude 3.5 earthquake struck near Rialto, California, rattling the Inland Empire and surrounding areas across Southern California. According to the U.S. Geological Survey (USGS), the quake's epicenter was located near Fontana, approximately 3.8 miles from Rialto and 4.5 miles from Fontana, at a shallow depth of about 3.6 miles (6 km).

Residents reported feeling the tremor not just throughout the Inland Empire, but as far south as San Clemente, and north towards Victorville. Despite the shaking, no immediate reports of serious injuries or property damage have surfaced.

This seismic event represents the fifth earthquake of magnitude 3.0 or greater in the area over the past 10 days, highlighting noticeable seismic activity in the region. On average, California and Nevada experience roughly 234 earthquakes annually within the 3.0 to 4.0 magnitude range, underlining the state's well-known susceptibility to frequent tremors due to its tectonic setting along major fault lines such as the San Andreas fault.

The region around Rialto and Fontana is known for frequent minor earthquakes. Historical records show that over the past century, several significant quakes—some exceeding magnitude 6.0—have impacted the broader San Bernardino County area. The recent cluster of tremors indicates continued tectonic movement beneath Southern California.

Residents who experienced the tremor are encouraged to report their experiences to the USGS to aid in seismic data collection. As precaution, Southern Californians are reminded to stay prepared for stronger earthquakes, given the area's active seismic activity.

In addition to this quake, Southern California experienced two other magnitude 3.5 earthquakes near Ontario shortly after midnight on August 6, amplifying the recent flurry of seismic events in the area. No injuries or damage have been reported from these subsequent tremors either.