Mine has been in for two days. We are on clay, and on a flood plain...so when it rains, we get WET! (yes, yes, i know that's sort of stating the obvious! Lol)
My boy quite enjoys his duvet days, so I don't see the point of him standing miserable in the muddy gateway.
It's not the rain coming down I keep him in from, it's the ground I worry about...don't want him pullingnanything, getting mudfeber, amd I'd rather keep him in amd let it dry and have nicer fields, than keep out for the sake of it and have them wreck the surface.