Chickens love going out in the rain as it is great worm catching weather. They do need to have access to run for cover, under a bush or table, even a patio umbrella.
Not only can Buff Orpington's tolerate the rain- they can tolerate floods(as mine have done on occasion) and... look at this.... they are apparently quite the swimmers.
Oh no way!!!! Did they get in on their own, or were they "helped"?