I always hunt rain, it is my absolute favorite hunting condition. I don't hunt downpours due to fear of loosing a blood trail, but anything less than a monsoon I will hunt. Today was drizzle mixed with some steady rain, and I was stuck in school!! Most of my best shot opportunity's are presented to me in the rain.
As far as equipment, if your bow is finished I would not even think about water getting in. If your arrows are properly tuned you don't have to worry about them getting wet, they will still fly . . .