@JoAnn1159, as @Emily487 said, I probably wouldn't. I've had the same situation a few times and while we sympathize with them, put yourself in their shoes. If you planned to leave because of a snowstorm, would you think a refund was in order? In a hotel, especially? I did give one guest, very early on a bit of a refund, because I felt sorry for her since she got altitude sickness, but that is because we had actually chatted back and forth beforehand and I just felt bad for her overall.
But, in this case, I would play it by ear and see how they go about it, but I would most likely not give a refund.