LOL Mine can hold it for days if the alternative is going out in a t-storm. Likey yours, rain is not a problem. Just if there is thunder involved. Common problem with goldens, not sure about other breeds. Where does yours like to hide? Mine generally hides under the bed, but one day I saw just the rear end of a dog sticking out of the closet. You guessed it, the rest of her was hiding inside! Silly girl!
susie
Our older dog is a mutt we adopted years ago. He'd go out in the flashing lightning and pouring rain.
Our Weim is the one that's afraid of thunder. She usually sleeps with us, but if there's a thunder storm in the night, we throw her blanket into our closet and she sleeps in there with only her head sticking out the closet door.
But if it's during the day, she doesn't hide, she just wants to be near you, so she'll wander around with us from room to room and just make sure she's lying close to our feet (of course, that's pretty normal for a Weim in any instance, since they tend to be "velcro" dogs.)