It struck at the shallow depth of 0.9km (0.6 miles) and its epicentre was near the city of Ridgecrest, about 240km north-east of Los Angeles.
A 6.4 magnitude quake hit the same region on Thursday at a depth of nearly 11km.
As yet, there have been no reports of casualties or of major damage.
The Los Angeles Fire Department said nobody had been killed or injured. A statement after the latest quake said the authorities had seen "no major infrastructure damage" after a survey of the city.
There were however reports of local power outages after the new quake. Officials said it was still unclear how much damage had been caused and how many people had been injured in the state.
"It was bad. Man. It hasn't stopped yet," local resident Jeremiah Jones told the Los Angeles Times.
Thursday's event wrecked some homes in the region.