I live not too far from you in Maryland, and I, too, have noticed that for about the last ten years the springs and summers have been rainier than they used to be. And since that started, my peonies which had had no trace of powdery mildew for 20 years, suddenly developed it, and I have had to fight it with Cornell spray ever since.
My iris that have flourished the best during this have been:
Beverly Sills, Bubbling Over, Dusky Challenger, and Absolute Treasure. Though Champagne Elegance did not bloom its first year, 2020, it is forming a beautiful clump, and I expect it to put on quite a show this spring, with multiple bloom stalks.
Many of my others are just hanging in there, but I know it's partly because of our huge maple tree casting more and more shade. I need to dig a new iris garden in a sunnier area, but I just don't have the physical stamina to do it.