I just moved around 35 chicks, some mostly feathered, most still in fluff with only wing feathers getting started. They're in a mini-tractor (portable coop) getting acquainted with some of the adults, some juveniles, and a bunch of crazy ducklings. This is their third day out. Today is hot, but most of the time we've been rainy and cool. The tractor has corrugated milky plastic on the roof and around one end to give them a three-sided area and a more open but roofed play area-so really, enough, but not all that much weather protection. They are so much more content. Instead of tweeting and eating constantly, they're running around pecking and scratching and getting to know the olders.
The juveniles were put out in the unheated greenhouse (freezing temps) at around the same age, in the same shelter but inside the unheated greenhouse with the hens, who spent the (often sub-zero) winter there. Chickens are a LOT tougher than most of us think.