The different weather, this summer, will affect fish behaviour, as will an abundance of feed.
There is another factor. You have specific go to lures ( red rooster, etc...) that you throw at the same pools. Over time, the fish will condition to not respond to that bait any longer and be more wary. A new bait, bigger, smaller, new colour. Give them something different. It is amazing what will work.
My fishing has been quite productive so far this year. I just keep doing things differently, and I always go out with a few options in the backpack.