M2.7 earthquake 6km SSW of Redlands, CA

A magnitude 2.7 earthquake struck 6km SSW of Redlands, CA on Sun, Dec 5, 2021, 3:10 AM PST (11:10 UTC), 11 km (7 mi) below the surface.

A larger quake followed: M4.0 5km WSW of Palomar Observatory, CA. This one was a foreshock.

Map

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

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.	Scale	Computed by	Notes
2.67	ML, local (Richter)	Southern California Seismic Network	Preferred · Final · ±0.246 · 32 stations
2.5	ML, local (Richter)	USGS National Earthquake Information Center	Reviewed · ±0.042 · 74 stations

35 people reported to the USGS what they felt; the strongest reported shaking was IV, light shaking.

Reviewed by a seismologist.

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

Within 100 km, magnitude 1.5 and up: 149 in the 60 days after this one and 44 in the 30 days before it.

The first 60 of 149.

From the USGS Earthquake Hazards Program and its partner networks, event ci39879567 (also filed as us6000g99b). Read Sun, Oct 4, 2026, 7:45 AM UTC.