The quake was recorded at 4:44 a.m. PT (7:44 a.m. ET) and was 19.9 km deep. It followed a 2.5 temblor at 4:15 a.m. PT that registered 25.9 km deep in the same area.
Lennox is an unincorporated area just a few miles east of Los Angeles International Airport.
There were no immediate reports of damage.