When we went in 2008 we visited AK on a day when rain was forecast - it was dreadful, the leaves and everything blocked all the places where water would usually drain away leaving swimming pools all over the place!
Gee Kate, I was going to suggest AK. Thought it would be sort of neat seeing the animals out in the rain. Never thought about how their behavior would change. I know that they heat/cool certain areas like on the lion pride region to attract animals to certain locations.. besides guess it would feel sort of authentic to be out on a safari in the rain.
Kind of weird. Never really rained on our visits over the years...or if it did it was just a passing shower (even once with a threatening hurricane...was just overcast and humid).