Personally, I've seen very few on rainy days to the point that I hardly hunt them anymore unless in a shooting house. Give me a cold, clear, calm, sunny day and I'm happy.
My daughter has killed 2 mature bucks on days where it was raining — and these were days where it rained like 4 - 7 inches. We sat in pop up blind tent those days. Have had other days were we saw nice bucks but didn't get shots.