Keeping outdoor cats warm in winter comes down to three things: a small, insulated, raised shelter, straw bedding that stays dry, and water that's checked often so it doesn't freeze. Big dog houses and fleece blankets, the two things most people reach for first, actually make cats colder.
The Ontario SPCA lists cats among the animals most vulnerable to cold, and says animals shouldn't be left outside for long when it's below freezing. If the outdoor cat is yours, the safest plan on the coldest days is bringing them in.
For barn cats and the community cats so many Torontonians feed on their back steps, this guide covers shelter, bedding, placement, water and the signs that a cat needs a vet.
If the cat is yours, start indoors
Your own cat has something most community cats don't: a warm house. The Ontario SPCA recommends that pets have a warm place to sleep, away from drafts and off the floor, and warns that cats, seniors, underweight animals and those with medical conditions are especially vulnerable in the cold.
On very cold or windy days, shorten outdoor time or skip it. Make sure your cat can always get back in, through a cat door or because someone's home. Keep ID current: a breakaway collar and tag, a microchip and, in Toronto, a cat licence. And if your cat is elderly or has an ongoing condition, ask your vet about winter.
Keeping outdoor cats warm in winter: the shelter
For keeping outdoor cats warm in winter, the shelter should be small, insulated and dry. The cat's own body heat warms it, so the less air inside, the warmer it stays. ASPCApro's guidance on community cat shelters is the most detailed practical source, and here it is in a table:
| Feature | What to do | Why |
|---|---|---|
| Size | Small and low; several shelters for a larger group | Holds body heat; big dog houses and crates are poor choices |
| Material | A foam cooler about 2 inches thick, or a double insulated plastic bin | Cheap, waterproof and insulated |
| Entrance | About 5.5 to 6 inches wide, cut several inches above the floor | Keeps out raccoons, rain and snow |
| Second door | Flaps on both if there are two entrances | Reduces heat loss; cats like an escape route |
| Height | Raised off the ground, with straw underneath, on a slight slant | Insulates from frozen ground and drains meltwater |
| Placement | Sheltered from wind, entrance facing a wall, behind a fence if dogs are about | Protection from weather and predators |
In Toronto you might not need to build one at all. The City's TNR page and the Toronto Feral Cat Coalition list partner groups that build and hand out winter shelters for community cats, among them Toronto Street Cats and Toronto Cat Rescue.
Straw, not blankets
Use straw, because blankets get wet and freeze. Blankets, towels and pillows soak up moisture from snow and breath, and then they freeze. ASPCApro says straw is the right bedding because it resists moisture and insulates, and that wet or dirty bedding should be replaced.
Use straw, the hollow, dry stalks sold as livestock bedding. Don't swap in blankets or towels; once they get wet, they make the shelter colder.
Pack it loosely so cats can burrow in, and check it through the season. Flattened, damp straw doesn't do much.
Water and food in freezing weather
Water is the hardest part of winter care, since a bowl can freeze within hours. ASPCApro's advice is to check water often, replace it when it's frozen, and put it where snow, ice and contamination can't reach it.
Set food and water near the shelter but not inside it, so spills don't soak the bedding. A covered feeding station keeps snow off the bowls if you can manage one. Feeding at the same times each day helps too, because the cats learn to come out while the food's fresh. Top up the water at every visit, and more often on the bitterest days.
Ask a vet before changing what a cat in your care eats for the winter, especially one with a known health problem.
Winter hazards around outdoor cats
Snow, salt and car fluids are the big three. ASPCApro advises clearing snow from all entrances and exits and checking shelters during storms, because a drift can seal a cat in or out.
Keep de-icing salt and ice melt away from shelters, food and water. Cats can swallow it while grooming their paws, and some products irritate the pads. The AVMA advises wiping feet, legs and belly after time outdoors to remove de-icers and antifreeze; for community cats, that means keeping feeding stations well away from driveways and garages.
The Ontario SPCA lists the signs of cold stress to watch for in any pet: shivering, a hunched posture, and lifting paws off the ground. It names prolonged shivering and slow, shallow breathing as signs of hypothermia, and notes frostbite often affects the ears, legs, paws and tail.
When an outdoor cat needs a vet
Get a cat to a vet or emergency clinic now if it's weak, collapsed, breathing slowly, shivering for a long time, or has ears or paws that look discoloured or black. Our guide to when to take your cat to the emergency vet lists more urgent signs, and the PetGrid map shows every vet clinic nearby, not just PetGrid ones.
For community cats, Toronto offers free sterilization through its TNR program. Caretakers do a short online course first, and every cat is ear tipped so others know it's been fixed. Contact feralcats@toronto.ca or 416-338-6281.
Questions people ask
What is the best bedding for an outdoor cat shelter?
Straw is the best bedding for an outdoor cat shelter. It resists moisture and insulates, while blankets and towels soak up water and get cold.
How big should a winter cat shelter be?
Small and low, so the cat's body heat can warm it. ASPCApro suggests an entrance about 5.5 to 6 inches wide, which also keeps raccoons out.
How do I stop outdoor cat water from freezing?
Check it often and replace it when it freezes. Put the bowl where snow and ice can't reach it, ideally under a cover near the shelter.
Can I get a free winter shelter for community cats in Toronto?
Toronto Feral Cat Coalition partners such as Toronto Street Cats and Toronto Cat Rescue build and hand out shelters. Contact them directly for what's available this season.
Should I bring my outdoor cat inside in winter?
On very cold days, yes, if you can. The Ontario SPCA says cats are especially vulnerable to cold and shouldn't be left out for long below freezing.
What does an ear tipped cat mean?
An ear tip marks a community cat that has been sterilized through a TNR program. Toronto's program ear tips every cat it admits.
The short version
Keeping outdoor cats warm in winter means a small insulated shelter raised off the ground, straw that stays dry, water checked often, and entrances kept clear of snow and salt. Pet cats are safest indoors on the coldest days, and any cat that's weak, shivering for a long time or has discoloured ears or paws needs a vet right away.
If the outdoor cat is yours, the free PetGrid app keeps their records, microchip number and vaccines in one place, and its map helps you find a nearby vet fast.
Keep your pet's records, vaccines and visits in one safe place. The PetGrid app is free for pet owners, with or without a clinic.
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