The best time to fish the Yakima River is very dependable on what style of fishing and depends on quantity versus quality of fish you want to catch. If you want to catch many fish but do not care about size I would recommend the summer, or if you want to catch few fish but bigger fish I would recommend the winter. If you want a mix of size and quantity I would recommend the Spring or the Fall and here is why.
The Spring offers us a Skwala Stonefly hatch which is the first hatch of the season where hungry trout start to focus more on insects on top as well as subsurface to suffice their appetite. This is a good time of year to target these opportunistic fish into eating a dry fly or a nymph subsurface. Elder trout are looking to spawn and all other trout are seeing a new food source coming down the river so this is prime time to present a Skwala Stonefly to willing fish.
Back to our summer time fishing, our river flows are very high and that means our bug life is active which means the fish have a lot of habitat and food source which keeps our bug life and water habitat at an all time high. When the water levels drop in the fall it creates low water conditions where are big fish are highly competitive on feeding grounds where smaller fish used to be. There’s only small water now.
The best time to fish the Yakima River depends on how you want to catch fish!
Once those levels drop the bigger fish push the smaller fish out of the major runs so our quality goes up but the amount of fish we catch goes down. Typically, our regular anglers book the Spring and Fall months and our first time anglers book Summer months. This is not to say first time anglers don’t book Spring and Fall and experienced anglers book only Summer. The best fishing on the Yakima River is from the middle of March till the middle of October!