El Nino?............I'll believe it when I see it...........
As far as hunting deer in the rain.....I've shot at least 2 local deer in the rain, but that was when we had a good acorn crop and were in oak forests. Really has little to do with their feeding other than they tend to feed more during the day (good thing).....Rut activity tends to slow down some during the rain in my observations.
One bad thing about rain would be following a blood trail.....I pretty much wouldn't hunt with a bow under those conditions (haven't had to worry about that lately)....2 cents