On June 2, 2016, the Seattle Times posted an insightful column by Jon Talton (@jontalton on Twitter) entitled Seattle housing: Is it a bubble? His conclusion: "Perhaps, but probably not."
Over at seattlebubble.com, you will find an interactive graph provided via Tableau Public. You can plot the year-over-year change in the Case-Shiller Housing Price Index for twenty metropolitan markets in the USA on a monthly basis going back as far as 1987 and, currently, to March 2016. See below for screen shot of the year-over-year change in the price index for the USA and the Seattle area for the past fifteen years (March 2001 to March 2016.)