The USGS reports the quake struck at 11:41 a.m. about a mile east/northeast of Key Center, and 11 miles northwest of University Place. The quake was fairly shallow at a depth of 3.5 miles.
There are no reports of damage or injuries but many people did report feeling the tremor.
"My windows started rattling really hard and then my walls shook and my floor... and it took me a while to figure out what was going on," said Linda Swenson in Gig Harbor. "At first I thought someone was at my door and was banging really hard and then I realized it felt like an earthquake."
She said it was real brief -- about 10-20 seconds, but the quake didn't do anything more than just rattle her a bit.
"My nerves are still shaking," she said.
Others took to Twitter to report they felt it:
@komonews thought the spin cycle on the ole washer was going crazy!— Jackson (@gmjackdtc) August 20, 2013
Mild shimmy in downtown Oly. Thought it was log truck going by. MT @komonews: USGS says 3.6 quake just struck about 13 mi SW of Port Orchard— Genghis Connor (@Genghis_Connor) August 20, 2013
@komonews yes! Felt it in Purdy!— Nicole Daugherty (@NickeeMeow) August 20, 2013