The first temblor, a 3.7 quake, hit around 3:41 p.m. It hit about five miles south of Mountain Center, and roughly 15 miles east-southeast of Hemet, according to the USGS.
Three more earthquakes, likely aftershocks, then hit the area shortly after.
A smaller quake measuring 2.1 struck, followed a larger 3.5-magnitude temblor just before 4 p.m. At least two small aftershocks, both less than 3.0, hit moments later.
No significant damage was immediately reported.
City News Service contributed to this report.