The first temblor was a 4.6 magnitude that struck at 2:51 a.m.
"We were sound asleep and the whole house shook and we all woke up".
The state Department of Transportation sent crews out to inspect bridges but no damage was found by Friday afternoon.
An overnight quake with an epicentre around 65 kilometres north of Seattle was felt in British Columbia. The natural disaster was felt around the sound from Arlington to Seattle and as far as Bremerton, CBS affiliate KIRO-TV reported.
Residents of Vancouver, Victoria and other spots near the border jumped on Twitter in the middle of the night to say they felt shaking.
The quake struck as millions of people in Southern California are on edge and anxious about their safety after two large earthquakes and more than 4,000 aftershocks.
David Caruso, a USGS geophysicist, told The Seattle Times the Washington state quake was due to a thrust fault, in which one side of a fault pushed upward relative to its opposite side.