I've had some of my best Steelheading days in really rotten weather.
One time we were on the Trinity River, California, at a put in, raining very hard, you could almost see the water rising, a father and daughter with their guide, after having flown in from Illinois, decided it wasn't worth it.. and left. I think they actually went home.
We both landed 5+ Steelhead.. I think I got 7? Great day!