I am assuming you are bringing a boat. Because of the Slots, I would say August if you already have developed local knowledge related to reefs and bar locations, getting in and out of harbors and the salmon fishing hot spots etc. and because August is when there is the highest numbers of big Chinook coming past including the big whites and you are actually allowed to keep them.
The downside is the locals call it Fogust for a reason and it can be thick and roll in fast and last. Having a good compass, a reflector, GPS Chart Plotter and a back up such as a good handheld GPS Chartplotter and lots of batteries is a good idea. Radar is also good idea for navigation if you happen to have it and for watching for other boats as there are a lot of them. On the other hand many of us with a lot of local knowledge fished for years in the thick fog and strong currents and around rock walls and reefs with nothing but a compass, a paper chart and a sounder.
If you don’t have local knowledge, you may want to go earlier in the summer for your first time and learn the area without having to fight fog., perhaps after they drop the Slot. For example even in clear weather every year we watch some without local knowledge run their boat a ground or suffer motor leg damage etc on the shallows at the mouth of the Sooke River on the way back to Sunny Shores to pull out, camp or gas up. The navigable channel there is not very wide especially at low tide.
As for Sockeye, the runs vary by year and we have to wait and see if they will give us an opening after the test fisheries etc and even if they do give us an opening it may be for the tail end of the run when most are past. That could make it tricky for someone who wants Sockeye to plan a trip and arrange vacation time etc. as they open it when they open it, if they open it and we sure don’t count on an opening anymore.