Small magnitude 3.5 earthquake 5 miles southeast of Ontario, California, United States

A magnitude 3.5 earthquake near Ontario, San Bernardino County, California, USA, was reported only 12 minutes ago by the United States Geological Survey, considered the key international and national agency that monitors seismic activity in the US. The earthquake occurred at a very shallow depth of 4 miles beneath the epicenter early morning on Wednesday, August 6th, 2025, at 1:02 am local time. The exact magnitude, epicenter, and depth of the quake might be revised within the next few hours or minutes as seismologists review data and refine their calculations, or as other agencies issue their report.
A second report was later issued by The Incorporated Research Institutions for Seismology (IRIS), which listed it as a magnitude 3.1 earthquake.
Based on the preliminary seismic data, the quake should not have caused any significant damage, but was probably felt by many people as light vibration in the area of the epicenter.
Weak shaking might have been felt in Eastvale (pop. 59,000) located 4 miles from the epicenter, Ontario (pop. 171,200) 5 miles away, Chino (pop. 85,600) 6 miles away, Rancho Cucamonga (pop. 175,200) 6 miles away, Upland (pop. 76,400) 6 miles away, and Pomona (pop. 153,300) 10 miles away.
Other towns or cities near the epicenter where the quake might have been felt as very weak shaking include Fontana (pop. 212,700) located 10 miles from the epicenter, and Corona (pop. 164,200) 10 miles away. In Los Angeles (pop. 3,898,700, 38 miles away), the quake was probably not felt.

Earthquake data:
Date & time: Aug 6, 2025 08:02 am (Universal Time) local time (6 Aug 2025 08:02 GMT)
Magnitude: 3.5
Depth: 6.51 km
Epicenter latitude / longitude: 34.02°N / 117.59°W (San Bernardino County, California, United States)
Primary data source: USGS
https://www.volcanodiscovery.com/earthquake/news/277354/Small-magnitude-35-earthquake-5-miles-southeast-of-Ontario-California-United-States.html