At what age can Guinea Keets live outside?
The coop is in a 3 sided shedrow barn, and has wind break baseboards on the mesh walls.
The weather here is currently 70s-80s during the day, and lows in the 50s at night.
I've always heard you need to start them out at 95F and you can drop them down 5F per week after that. I've heard that you can put them at regular temperatures once they are fully feathered. I've heard 6 weeks. I've heard not to let them free range until all the down is gone from their heads. Basically, I think once they are fully feathered they can take much cooler temperatures but I'd want to let them have access to a heat lamp in a draft-free spot at night. I think 50F is pretty chilly for a small keet even if they are huddled together for warmth.
I just started with guineas this year. We got them at four weeks old and they were put straight into their pen. The lady we got them from said they were good to go outside once they were fully feathered (had feathers rather than 'fluff') we kept a heating lamp in their pen for them too.
I don't know if you already have other chickens or a heating lamp but if you haven't gotten one yet, I'd be careful about choosing one... our coop got burned down from our heating lamp being too hot and getting knocked against the wall.