I taught my hens to sleep in the coop. So every night at sun down they go to bed. Where I live the weather changes quickly. I didn't want to run the risk of chickens getting caught in a storm during the night while I'm asleep. They have a large run that they all day but they know to head inside at dark, or when a storm comes. Chickens kinda become night blind, I guess is the best way to put it. If they are used to sleeping outside at night then they more than likely won't seek shelter in the coop during a night storm. Even if they sleep in a coop, if they don't make it to bed by sundown they risk not making it shelter. 27 degrees is still below freezing and they will need cover from the breeze.
