I would recommend not packing a bunch of clothes for baby in the hospital. I did for my first and they kept getting dirty which just meant more laundry for me when I got home, so with my second I only brought a going home outfit and used what the hospital provided while I was there. I would say a short sleeve onside and light pants, if for some reason it's a chilly day have a receiving blanket or use the one the hospital gives you to put around him if you think he needs it.
I'm from Oregon too!!!!!!! I'd say a onsie and cotton shorts/thin pants. Its been super hot where I am too, but ya never know, it could be raining in 2 weeks :)
I picked a super cute sleevless onsie that says "see ya latet alligator" on it. But also have a small blanket packed incase it is cold
I am packing a onsie, socks and bottoms for a going home outfit and a blanket for the car ride just incase I think the car is too cold on the way home.