the rain is not gonna hurt the bow....wax the string prior to hunting, actually you should always keep the string waxed. keep all metal parts lubricated with oil. after the hunt, wipe down good and do NOT store in case until completely dry.
been bow hunting for many years and i have never let rain stop me..just have to make a good shot for trailing. good luck to you and your adventures with the bow.
Ronnie Smith's Outdoor Adventure Prostaff and Cameraman