How to Keep Chickens Warm in Winter
The counterintuitive answer: do not heat the coop. Chickens tolerate cold well. What kills them is damp air and ammonia — both made worse by sealing a coop up.
Why sealing a coop is the wrong move
Chickens breathe out a surprising amount of moisture. In a sealed coop that moisture condenses on combs and wattles at night — which is exactly how frostbite happens, at temperatures well above what you would expect.
Ammonia from droppings builds up at the same time and irritates the respiratory tract. A sealed coop produces sick birds; a ventilated one produces cold but healthy birds.
The ventilation rule
- Vents high, above head height — air leaves without blowing on the birds
- About 0.1 m² of vent per bird as a starting point
- Never blocked, even in a hard frost
- No draught at roost level — that is different from ventilation and does cause harm
Should you heat the coop?
Generally no. Reasons against:
- Fire risk — heat lamps are a leading cause of coop fires
- Power cuts — birds acclimatised to warmth suffer badly when it fails
- It masks the real problem — if the coop is damp, heat makes it worse, not better
- Acclimatisation — birds that experience autumn cold handle winter far better
Exceptions: prolonged temperatures below about -15°C, or breeds with large single combs (Leghorns, Minorcas) in hard frost.
What actually helps
| Measure | Effect |
|---|---|
| Deep bedding (15 cm+) | Compacts and composts, generating gentle warmth |
| Wide flat roost bar | Birds cover their feet with their bodies |
| Vaseline on combs | Reduces frostbite risk in hard frost |
| Extra corn in the evening | Slow-burning energy overnight (in moderation) |
| Windbreak, not insulation | Stops draught without sealing |
Water in freezing weather
Chickens drink as much in winter as summer, and a hen that cannot drink stops laying within days.
- Bring water in at night, or use a heated base
- Check twice daily in a hard frost — a thin film of ice is enough to stop them
- Do not add sugar or salt to lower the freezing point; it is not effective at safe concentrations
Frostbite: what to look for
Pale, waxy comb tips that later turn black. Large-combed breeds and roosters are most at risk.
- Do not rub or massage frozen tissue
- Do not use hot water — warm gradually
- Vaseline before a cold night prevents most cases
Moulting in winter
A hen that moults late goes into winter with thin feather cover. She needs 18–20% protein during regrowth — feathers are about 85% protein. A handful of sunflower seeds or a little meat helps.
Common questions
Do chickens need heat in winter?
Usually no. They tolerate cold well and are at more risk from damp, sealed coops. Heat lamps are also a common cause of coop fires.
At what temperature are chickens too cold?
Healthy, acclimatised birds handle -10C and below. Risk rises below about -15C, or for large-combed breeds in hard frost.
How do you keep chicken water from freezing?
Bring it in overnight, use a heated base, or check twice daily and replace it. A thin ice film is enough to stop them drinking.
Should you insulate a chicken coop?
Insulation helps less than ventilation. Prioritise high vents and a windbreak over insulation, and never seal the coop completely.
Complete winter care and first-year guide: Backyard Chickens for Beginners.
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