I have a small flock of Chickens who are about 6 weeks old, the other 3 are 12 weeks old, I know the 12 week olds can be outside, however it is the 6 weeks old I am concerned about, the lows have been in the 50's to 40s (which for Florida, is cold) and I didn't know if they could go outside in that.
6 week old chiks
Oh yes, the 6 week olds can totally handle it! Oh what I would do for those temps here! That being said, if you are still using a heat lamp on them I would wean them off of that first. Get them used to "normal" inside temps. Mine went from 70 degree temps to 50 degree temps at 5 weeks old, no problem.
Ours have been living in 20 degree weather for a couple of weeks...to be fair, that's cold for here too. Normal is 30's and 40's. Mine are 16 weeks old but have been outside since 5 weeks old, just fine. SO if yours haven't had a heat lamp they should make the transition just fine. As chicken parent YOU may worry about them for the first night or two......don't worry, you'll be fine too!