I can’t tell you how cold it was last night because the batteries in my remote thermometer sensor froze and quit transmitting to the receiver in the house! Batteries don’t work very well in cold weather–something to keep in mind if you have to depend on them. When I went out to check on the hens at 8:00 a.m., it was -18F. (The lowest temperature in Wisconsin at that point was Rhinelander at -29F and the highest was -13F in Milwaukee.)
It’s just like the good (?) old days back in the 1970s and 1980s when I was living in central Wisconsin, only the cold snaps lasted several weeks rather than several days back then. (We used to pull down our hoods and unzip our parkas when the temps would rise to zero and the single digits!) The high for us today was -10F. Now the sun is going down and it is clear as a bell. At dusk the temperature was -12F. Tonight’s forecasted low is -18F. All right then.
When the temperatures drop into the teens, there are a few things that I do to keep my very small flock warm enough to avoid problems. First, I make sure that the floor of the coop has a 6-8 inch cover of insulating hay bedding. I usually bed with pine shavings for ease of cleaning (it’s also cheaper than hay), but when the weather gets really bitter and the hens have to be cooped up, I start to gradually add up to a half of a small square bale of hay. The hay has the added benefit of keeping them busy. They like to tear the flakes apart and eat the green leaves and any bugs or weed seeds. When they have done this, the bale is spread nicely, and they have a cushion against drafts and the cold floor. (My coop is raised on brick piers, so there is a gap underneath it, which makes the floor very cold in the winter.)
I also lean hay flakes against the cracks in the door frame and door jamb to cut down on drafts of cold air. Wild rabbits and deer work on this hay a bit, so periodically I have to renew it. As the chicks turn over and spread the hay bedding inside the coop, it plugs the crack at the bottom of the door as well.
My coop is well insulated. (Someday, when I am no longer keeping chickens, we will be able use the small building for a man or woman cave after replacing the floor and wall board.) It was 26F in the coop –39 degrees warmer than it was outside this morning. I like to keep the coop between 20-30F during cold snaps. They can certainly take a colder temperature if they are protected from drafts and aren’t molting. (I let the chickens out into their yard when the outside temperature hits 20F.) I just don’t like it to get to a lower temperature in the coop than that at which I am willing to let them out into the yard. (Frozen combs and feet–I’m just not willing to go there.)
With large flocks, the birds themselves heat the coop. My birds can raise the coop temperature about one degree per bird, so I use a small radiator that has the heating element immersed in oil to heat the coop during these cold times and a heated water font to keep their water in a liquid state. The radiator has two temperature ranges. Usually, I only use the lower range (600 watts, approx. 6 cents per hour). The higher range (1500 watts, approx. 15 cents per hour) is only needed on below zero days and nights like these. It isn’t always running hard during the day because the coop benefits from solar gain. I chose the oil radiator over an electric bar to avoid the chance of fire. I also raise the heater above the bedding on bricks and sweep down cobwebs frequently. (Cobwebs aren’t a huge problem for me but might be in a coop housing more birds that doesn’t have adequate ventilation.)
It’s nice and warm here in the house now, too. My husband discovered that our coop was better insulated than the far end of our house. He crawled up in the attic space early this week and laid down a bunch of bats of insulation! I hope you are all staying warm, too. Begonia