Not really depressing. More like frustrating, I think. I grew up in an arid climate. The day I finally left Los Angeles it was 106F/41C. So I like the cool and rain. My favorite climate feature here has always been that the ambient water temperature in my darkroom never exceeds 68F/20C. Even during the "hottest" month of August. In LA I used to process with 84F/29C water. Or try to.
But sometimes 10˝ (or last year 11˝) months of near non-stop rain can get frustrating. The summer before last we had only about 3 weeks in August of continuous, predictable non-rainy days, remember? Not so bad using my 35mm Canonet QL17. But a bit more of a problem with my 8x10 Calumet C1. Can't really tuck that guy under my jacket.
So I think we do the OP an injustice if we act like the Chamber of Commerce and don't tell him the truth when he asks. That's why I gave him a realistic shutter/aperture combination to expect. And realistic light and contrast levels he will encounter. And a suggestion for an alternate way to get out and do some photos without drowning. And a NWS link to monitor the Seattle weather in real time up to the point he eventually arrives.
Hopefully he can actually do something with that information to enhance his visit photographically.
If I were visiting Phoenix in late August and asked what's it like I'd darned sure want somebody to tell me the truth. That sometimes it gets so hot that the airport has to shut down because the air is so thin that planes can't get off the ground by the end of the runway. That's hot. And would probably affect how I approached my picture-taking. And safety while doing so.
Heck, I didn't even begin to describe the ritual November flooding episodes. Here in Snohomish County we've had three 100-year floods in the last 12 years, or so. Twice local levees have breached and flooded the valleys for months. I know every cut-off-by-flooding highway choke point by heart. One flood was then followed by a massive ice storm that dropped huge Douglas firs that just missed my house.
This is an interesting corner of the world...