How cold is too cold???


Jan 20, 2020
Port Hope Simpson (Labrador), NL
This is our first year with chickens and where I live in the winter it can get to -40°C with the windchill. We installed an extra light in their coop in the past couple of weeks because it was 2° on the floor in their coop, so up in the roost next to the bigger light it was probably 10°. Now that we have the extra bulb in there it can get up to 17° in the afternoon on the floor so that's in the 20's up in the roost. So my question is how much cold and heat can they tolerate?


Jun 24, 2019
New Hampshire
It depends on the breed if you have ones that are cold hardy like Orpingtons they should be fine in a draft-free coop If you have chickens with large combs like Leghorns you should try and keep the temperature a bit warmer. As for heat, most chicken breeds are fairly heat tolerant as long as it doesn't get too much above 100 degrees. If you are worried about heat in the summer you can give you chickens a wading pool or plant some bushes for shade.

Wee Farmer Sarah

Free Ranging
Oct 8, 2018
North Central Massachusetts
I have to be honest, I'm not a fan of artificial heat in the chicken coop. At 2C, it is above freezing. I live in Northern Massachusetts and have had temperatures down below -20C and the chickens were fine. If the chickens are out of the wind then the wind chill is not really a factor. Keeping adequate ventilation and clean, dry bedding is more important. Chickens are covered in a warm down coat that keeps them pretty toasty. Make sure their roosting bar allows them to cover their feet with their feathers. If you really feel the need to add heat, there are warming plates that are fairly safe to use in the coop. The first winter is always the hardest but it does get better. Best of luck with your flock.


Free Ranging
Jul 3, 2016
WA, Pac NW
My Coop
My Coop
They do better with cold than heat. They can start panting in heat as soon as 85F (30C) and once you get into 100F+ (37C+) you may start seeing heatstroke and heatstress especially in weaker or older birds, or birds that don't have access to any way of cooling off, leading to death.

Now this is a very extreme example, but: The chickens survived below -50C without any heat.


Free Ranging
11 Years
Feb 2, 2009
Southeast Louisiana
Read this. It's by someone who probably understands that -40 C = -40 F but you are talking about windchill. If they are out of the wind windchill isn't a factor. Air temperature where they are is what matters if it is calm. So that is one of your goals, make it calm.

Alaskan’s Article

It's not a "one temperature fits all". There are different factors that @Alaskan goes into. I'm not going to try to repeat them, you need to read the article, but what works for one at a certain temperature will not work for all.

Mrs. K

Free Ranging
10 Years
Nov 12, 2009
western South Dakota
Do not think warm, think DRY. Dry birds out of the wind, are pretty warm birds. We have had -35 F here, and my chickens were just fine.

The problem with adding heat, is people want to close up the coop to trap the heat in. What you trap in is moisture, and damp chickens are cold chickens. The above post is correct, worry more about adequate and deep enough dry bedding, keeping the bedding fluffed up (sprinkle it with scratch, and the girls will fluff it for you). Keep the ventilation wide open on the side away from the prevailing wind.

Fresh air, good bedding are much more important that being warm. Chickens keep themselves warm.

Mrs K

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