There were no reports of damage or injuries, mainly due to the sparse population near the epicenter.
The U.S. Geological Survey said the quake struck at 4:45 p.m. local time and was centered about 47 miles north of La Paz at a relatively shallow depth of only six miles.
Two aftershocks registering magnitudes of 4.2 and 4.8 occurred within the following hour.
The seismic activity occurred along a boundary of the Pacific, which has moved slowly over the millennia to separate the Baja California Peninsula from the Mexican Mainland.