What do you mean? Are you planning to put them outside during the day? Or 24/7? I have ducklings that are almost 4 weeks old, and they do fine outside during the day. It has been really warm around here though. I would advise that you don't put them outside permanently until they are or are almost fully feathered. I put ducks outside before they were fully feathered. they acted fine. Then one day I walked outside to one of them dead, which left me with one, who was really lonely. i don't know if that's what caused it, but it definitely could have been. i know they don't need to be COMPLETELY feathered. I have a picture of two of my ducks laying together with a gate in between (they were separated, cause the other wasn't fully grown). In the picture she still had a little bit of baby fuzz on her head, and I put her out there about a month before that and she did fine (after the other one died, I brought her in for a while longer)