The US Geological Survey said there was "a low likelihood of casualties and damage" from the quake.
The epicenter of the quake, which hit at 6:49 am (local time) was located 157 kilometers west of Ferndale, California at a depth of 6.2 miles (10 kilometers), USGS said.
"Overall, the population in this region resides in structures that are highly resistant to earthquake shaking, though some vulnerable structures exist," it said, putting the likelihood of fatalities at low.