M2.6 earthquake 2km E of Willowbrook, CA

A magnitude 2.6 earthquake struck 2km E of Willowbrook, CA on Sun, Sep 25, 1983, 9:08 PM PDT (04:08 UTC), 13 km (8 mi) below the surface.

A larger quake followed: M3.1 6km SSW of Redlands, CA. This one was a foreshock.

Map

Where this earthquake was located, with the others nearby. Select one for its page.

No one has reported feeling this quake to the USGS.

Reviewed by a seismologist.

Distance and direction from each place to the epicenter, with its forecast.

Within 100 km, magnitude 1.5 and up: 156 in the 60 days after this one and 36 in the 30 days before it.

The first 60 of 156.

From the USGS Earthquake Hazards Program and its partner networks, event ci15723. Read Fri, Oct 2, 2026, 4:07 PM UTC.