this thread reminds me of a couple of guys I used to know
one is a guy I have both rifle- and bow-hunted with. once we were out (with rifles), and it started raining. he said he was ready to head home - because it started raining.
the other is a guy my brother rifle-hunted with once. he went hunting even though it was raining - but he kept his rifle wrapped in a plastic bag so it didn't get wet.
i know this doesn't answer your question - but the thread reminded me of them!
my answer is - no, the rain won't hurt your bow. mine have been soaked completely many times, and they still shoot just fine. you should dry it and clean it up, but it will keep working.