Best to be safe than sorry with babies. Mine would've been left out, but at that age mine were also integrated to the flock with access to the coop and run clutter for shelter if needed, so I didn't worry about them getting too rained on.I do have (5) 6 week old chicks that just moved into the run/coop area (separated from the other girls for now) i can’t keep them separate and dry at the same time so brought them inside in the pop up brooder until the bed time .. that was the right move right? they are too young to be out there?