i dont store it out in rain but if I am hunting...I dont fret too much about it. I make sure my glass backed bows are good and rain wont much hurt them though it can get down in the wood and raise the grain if bug spray has eaten the finish.....nothing a light sanding and spray with varathane or another product wont remedy. In addition to that...on both glass backed and self/backed bows...a coat of paste wax a couple times a year is good to help keep it sealed.
Where I live the humidity can be in the 90%+ in early season so it is nearly as bad as rain in pushing moisture into anything not protected or sealed.
I use my bow as a tool...I hunt with it in mud, heat, rain and snow...afterwards I clean it as needed...check for damage or compromises...take care of it and then hang back on rack for next visit to backyard to shoot or woods to hunt.
they are tougher than some of you admit....yes they can be works of art but they are still just a fancier tool.