Bring your rain boots and raincoat! Don't bother with an umbrella....its the mark of tourist
Not true. I am born and raised in the PNW and I (and everyone I know) carries an umbrella when it's raining. That's one of the myths "locals" like to spread about this area. I have lived in or around Seattle for a long time.
Born and raised as well. Never carried an umbrealla, very few people I know do, and they are newbies. I have been stabbed by many a tourist carying an umbrella.
If you are here on the first Thursday of the month, check out the art walk in Pioneer Square. It's free and has tons of fantastic local artists. Also, SAM (Seattle Art Museum) is free on first Thursday.
Check out Bleu Bistro on Capitol Hill, the Lavendar Cosmopolitan is the best cocktail in the city.
The Pacific Science Center is AWESOME (not just for kids, I have tons of fun there as an adult) and right now they have king Tutu exhibit. Check out the laser light shows as well.
The Elysian Brewery, great beer and amazing food.
Go see the Troll under the Aurora Bridge in Fremont. While your there, eat at Blue C Sushi (gluten free tamari on request!)
Central Cinema in the Central District is a 21 and under movie theatre that shows classic movies (from every decade) and serves beer and food while you sit at tables.