How cold is too cold for hens?

30 degree's is about the lowest a chicken can go on her/his own, I would recommend getting a red light! It helps heat the chicken coop but be cautious because chickens make body heat which will most of the time keep them warm but its hard to keep up under 30 degree's also do not forget that if you have around 8 or more chickens they will make some body heat, though do not forget sometimes its alittle hard to make that much on their own, also make sure that the water they have does not freeze, or it could harm the chicken! Good luck!

 

Perhaps you could build some shelters for them. Don’t know what your setup looks like some photos might help so we could give suggestions.
Wind blocks are nice. Somewhere where the cold wind doesn’t get to them. Even stacks of hay bails (making a box like structure) is good.
Your temperatures are cold can they access the coop?
Any scraps (plywood, pallets, tarps) can make a good fortress to huddle in.
Pictures definitely would help.

You are talking about out in the run right?

 

Chickens can definitely tolerate temperatures much lower than 30 degrees. Most of the time a light is not necessary. I had temps below zero last year and they were just fine.

The important thing is that they are dry and can get out of the wind. Chickens warm themselves by puffing their feathers a bit and trapping air between their feathers. When feathers are wet or constantly disturbed by wind they cannot self-regulate.

If you don't have a coop, I'd recommend getting one or making some kind of structure where they can get out of the wind. Something like a coop is helpful because it is enclosed and easier for a group of chickens to warm up that air, just make sure it also has ventilation because humidity in the cold is undesirable. The ones who are molting may be too cold depending on how hard of a molt they are having. Extra protein will help all of them, but the molters especially.

 

It went down to -22*F a few years ago with 24+ inches of snow. My girls made it just fine with no added heat, and some were molting heavy (yes I was worried). I did have a time getting the coop door open,,, Doh, it opens both ways,,,

 

Some breeds tolerate cold better than others; same for heat, it depends on the breed.
What will push a chicken into hypothermia is being wet and cold. If your chickens are in a run then make them a shelter as @[email protected] and @Firefoot mention.
Wind chill is another factor so once again a shelter is advisable.
The chickens here will happily forage at -5 centigrade, 23 F.
Lots of food, not just protein, helps. Food means calories and calories means heat.
Moulting will of course decrease their abiltiy to fluff up their feathers and this in turn will effect their ability to withstand cold temperatures.
In my experience chickens are reluctant to return to the coop in daylight hours no matter what the weather and prefer to seek shelter outside.
In short, build them a shelter, preferably one that has a wall facing the prevailing wind.

 

30 degrees isn't that cold. Sometimes if there are sudden temperature drops birds will huddle and shiver. Shivering is the bodies way of warming up and isn't always a bad thing. Chickens will also stand close to share heat. Too often people put on the heat when they see these behaviors. The birds are going through an acclamation process. They will often be fine a few days later. Keeping them dry and well ventilated is more important that worrying about keeping them warm. Even a chicken in a full molt is warmer than any human. Birds are equipped with a good coat of down and feathers and they don't feel weather the way humans do.

People will continue to debate heat or no heat. I personally can say it isn't necessary to temperatures down to the -20's. That's how cold it gets here. I've kept silkies and frizzles amongst other breeds. They all do fine when properly housed with a few extra things like unfrozen water, a good ration, some scratch to get them moving about, hay or straw to stand on outside, thick bedding and proper roosts. A nice facing south window for some sunshine is always welcome on cold days as well.

 

Our chickens have always been just fine with no additional heat, just areas they can get out of the wind in. It frequently gets down to -10 and occasionally as much as -20. Last year we had a lone hen we couldn’t catch (she wasn’t one we had raised) running around outside all winter long, living in a shell of a camper despite a few cold snaps of -30 for weeks at a time. She was just fine and laying eggs. Chickens are hardy little buggers.

 

Tell us about your flock....
How many and how old?
And your coop and run, dimensions and pics.