It is always possible and worth a try. I have friends who fish gear in area 11 around Tacoma and have been picking up a few coho, the largest being around 4lbs. In the past, some decent days could be had in area 9 on the years it has opened on July 15th.
I have found that July can be a great time to fish for the local beaches at least in area 11, though it can be hard to figure out what the fish are feeding on in the way of bait size. I had luck in July all the way from a 1 inch bait fish fly up to a 6" fly. I also have still in early July at times had fish still take clam worm patterns even though I believe the hatch is over most years by July. A clam worm pattern can be matched pretty well with a simple wooly bugger in blacks and browns. A good size selection of deceivers or other bait fish patterns is also a must. Switch your flies around a bit to find out what might be on the menue that day.
if you are fishing for SRC's which appear to always be in season, using gear appropriate for these fishes, using a technique appropriate for these fishes, just how can you be tickted for fishing for another species out of season?????? i would suppose if you had a salmon in your cooler, that would be a different situation.