I enjoy hunting in the rain (not a toad strangeling downpour, but a decent rain is OK). I generally still hunt in the rain as the wet conditions make for quiet walking. I do a lot of glassing, so a microfibre wipe is important to have to keep the lenses clean. I have had very little luck on stand in the rain. Seems like around here the deer do not move much in the wet weather.
Keep in mind what is important to all wildlife (food, water, cover), and since water is not lacking they will be looking for the others.
I am willing to hunt bedding areas that i normally stay out of in the rain since it dampens down noise and scent. Gotta watch the wind currents though, they can be tricky.
Keep the wind (what little there may be) in your face, go slow, look hard and as most folks have said be sure of the shot.
If the rain is too heavy, go anyway. I have spent most of the day in the truck reading a book or napping just so i could be in there hunting for the 2 or 3 hours the weather let up or the rain stopped. If the wet weather sticks around for severeal days, whatever breaks occur will see a lot of movement.
Now... that's the way it works here, and in a few other states I have hunted. Getting rained on while hunting beats staying dry at work (or home I guess).
Good luck.
OkKeith