We lived in Bellevue for about 18 months and the weather was beautiful. Almost everyone we met said the whole "it always rains" thing is just something they tell people so they'll stay away.
No, March '13 to Aug '14. But yes, many people called it a mild winter. While we had previously spent 5 years in Dallas, and 4 in Boston. My wife is originally from Idaho, and I from Michigan, anything less than multiple feet of snow, is "mild" :)
I moved from a pretty dry state to the Potomac valley, and noticed that if I happened to mention Seattle people would say, But it rains there all the time. The ground that we were standing on might be soft from recent storms, mushrooms might be sprouting around our feet, but Hey it rains in Seattle.
I lived in Bellevue for about 21 years, so I've got a bit more perspective.
It's not really that rainy, but it's grey 9 months out of the year for sure.