What tempature is safe to let my chickens outside

[the girls club]

I live in Ohio. I have new 4 month easter egger chickens with my one and a half year old golden buffs. The 4 month old chickens seem fully feathered. I have a very well insulated coop with a heat light in the coop. My question is how cold should it be outside to keep the chickens in the coop and not let them outside

 

[Wyandottes7]

At four months old, she'll probably be fine going outside even in freezing weather. Most birds, by the time they are four months old, have most of their adult feathering and can handle cold weather well. You can let her outside, though she probably won't like it much.