Water temperatures in June will be in the low 50's, and visibility varies but is unlikely to be more than 20 feet at best, and may be significantly less. There's a TON of life in the water at that time of year, though.
We have a number of good charter companies, but there is also a LOT of very easy access shore diving which is very good.
People dive wet here. I don't know how, but they do. There is no thermocline to speak of -- what you get into is the same as what you find at depth.
Check back in this forum when you're closer to your arrival dates, and you'll be sure to find people who will be delighted to meet up and dive with you. We're a sociable bunch, we PNWers, and always looking for an excuse to dive (like we need one).