How Do You Make A Stray Cat Warm Box?

Outdoor community cats, such as strays and ferals, are vulnerable to extreme cold during the winter months. Unlike pet cats who live indoors, community cats lack access to climate-controlled shelter and must find ways to stay warm outside. Prolonged exposure to freezing temperatures can be dangerous and even fatal for cats. Making an insulated, weatherproof shelter can help community cats better survive frigid winters when no other housing options exist. This guide explains how to create a warm box shelter tailored to the needs of outdoor cats.

Choosing a Box

The ideal box for a stray cat shelter should be waterproof, sturdy, and the right size and shape for the cat. According to Alley Cat Allies, the box should be about 1.5 times the length of the cat from nose to base of tail, and tall enough for the cat to comfortably stand up inside A plastic storage tote or Rubbermaid container works well since it is sturdy, waterproof, and comes in various sizes. Be sure to choose a box with a lid or way to create a doorway/opening.

Opt for a rectangular container rather than a square one, as cats prefer to curl up in cornered spaces. Avoid overly large boxes that are drafty. The optimal size allows the cat to fits snugly and retain body heat. For multiple cats, size up accordingly or provide multiple shelters. Look for durable plastic that won’t crack or warp in extreme temperatures.

Lining the Box

It is very important to line the inside of the box with insulating and moisture-protecting material before placing it outside. Straw or pine shavings work well to provide insulation and allow cats to burrow in for added warmth. According to How to TNR | Feral Cat Winter Shelter, “Straw is perfect – it’s loose, dry and provides added insulation.” You can also use bubble wrap or shredded newspaper for insulation. Do not use towels or blankets, as these can retain moisture and get cats wet.

Keeping cats dry is crucial, as wet fur loses insulating abilities. Make sure any lining materials are loose and fluffy enough for cats to dig into. Compacted, damp bedding can lead to hypothermia. Always replace wet bedding to ensure cats stay warm and dry all winter long. Proper insulation and moisture protection is key to making a safe winter shelter.

Entrance and Exits

Providing two exits for a stray cat shelter can help trap heat inside. The openings should be positioned on opposite sides, allowing cool air to flow in one entrance and warm air to escape from the other exit. Stray cats have different preferences, so having two exits gives them options and prevents them from feeling trapped. According to Alley Cat Allies, multiple exits also provide escape routes in case a predator blocks one entrance.

The size of the entrance holes matters too. Each opening should be just large enough for an average-sized adult cat to fit through. The Feral Cat Coalition of Oregon recommends sizing holes at least 5 inches high by 6 inches wide. Cutting rectangular flaps instead of circles can make it easier for cats to come and go. Avoid making the entrance holes too big, since it will let out more heat. You may need to adjust the size based on very large or small cats in your area.

When cutting entrance holes, be sure to use a utility knife safely with caution.


It’s important to pad the inside of the winter cat shelter to provide insulation and protect the cat from the cold ground. Some good padding options are Mylar blankets, or even sheets of cardboard.

Avoid using fabrics like towels or blankets, as they can absorb moisture and get wet. Wet fabrics will make the inside of the shelter very cold. Stick to waterproof padding materials as much as possible.

Aim for at least 2-3 inches of padding material throughout the floor and walls of the shelter. The padding creates dead air space which helps insulate the interior.

You can tape or glue the padding to the inside walls and floor. Make sure there are no loose edges that could catch on the cat’s claws or face.

Replenish the padding as needed throughout the winter if it gets worn down or wet.

Weather Protection

Wind and precipitation like rain or snow can be very dangerous to stray cats seeking warmth and shelter. It’s important to provide flap protections from the weather elements to keep the inside of the box dry and warm. Here are some tips:

Cut a flap in the opening of the box and attach it with duct tape or industrial strength velcro. This allows the cat to push its way in but protects from wind and rain when closed. The flap should open inward so it falls back down when the cat enters (Alley Cat Allies).

Make sure the flap is not too heavy for the cat to push through. Test it yourself first before setting up the shelter. It should swing open easily but not blow around in high winds.

Attach the box to a wall or stake it into the ground so it doesn’t blow away. Use bungee cords or rope to secure it. You can also place bricks or other heavy objects inside the bottom of the box for stability (Neighborhood Cats).

Check periodically that the box remains protected from precipitation. Make any needed repairs and replace the flap if it gets worn out.

Placement Tips

When placing the warm cat box, it’s important to choose a location that will provide shelter from the elements. Ideal spots include under porches or decks, against the south or east side of buildings, under bushes or dense shrubs, or tucked beside dumpsters and waste bins. These areas can provide protection from wind, rain, snow, and cold temperatures.

Avoid placing the box in direct sunlight or exposed, open areas. Also do not put it near busy roads or walkways where it may startle passersby or get kicked over. Garages and sheds can seem like good spots, but opening doors can scare cats away, and chemicals or machinery may be hazards. It’s also best not to place boxes right next to each other, as cats are solitary and prefer their own space. Leaving a good amount of distance between boxes prevents territory disputes.

Elevating the box off cold, wet ground provides insulation. Put down a base of wood pallets or bricks before setting it down. Packing straw underneath gives extra protection. Make sure the spot does not accumulate water or snowmelt, which can freeze into ice and make it uncomfortable for cats.

Ongoing Care

Caring for a stray cat warm box is an ongoing process. It’s important to periodically check on the box and perform maintenance as needed. Some tips for ongoing care include:

Note the box may need refreshed bedding if it gets soaked or dirty. Replace the straw, blankets, or other lining material as needed for cleanliness and warmth. Check for signs of pests and thoroughly clean the box to prevent infestations.

Check for occupancy and damage. Look to see if a cat is actively using the box. Also inspect the box, entrance, and any protective covering for wear and tear. Make repairs as needed to ensure the box remains functional through the winter.

Remove snow if necessary. Heavy snow can block the entrance or collapse the roof. Carefully clear snow when accumulation occurs.

Continue feeding nearby. Keep providing food and water in the vicinity of the box so cats are nourished and encouraged to use the shelter.

Monitor the community. Stay alert for newcomers who may need access to the shelter. Also watch for signs of illness and contact a vet if any cats appear unhealthy.

With periodic maintenance and monitoring, a well-built stray cat warm box can provide life-saving shelter all winter long.

Food & Water

It’s best if you can place food and water near the stray cat’s warm box. This will encourage the cat to stay close by and have easy access to sustenance. According to Alley Cat Allies, “Building a feeding station is the best way to feed community cats during the cold months. It will shield food, water, and the cats from the elements.”

When setting up an outdoor feeding station, look for a sheltered spot that is out of the wind, rain, and snow like under an eave or deck. You can buy an insulated cat shelter with built-in food bowls or make your own feeding station. Use plastic storage bins, Styrofoam coolers, or even cardboard boxes to create an enclosed space. Cut an opening on one side just big enough for cats to go in and out. Place food and water bowls inside. Having a top will help keep supplies dry.

PetMD recommends feeding cats on a consistent schedule during winter so they know when to expect meals. Canned or wet food can freeze in cold temperatures, so dry kibble may work better. Check food and water supplies daily to ensure they haven’t frozen over or been knocked out of place by wind or animals. Provide fresh water by changing it frequently.


Building an effective warm shelter for stray and community cats during winter is crucial for their health and survival. In this article, we discussed some key steps for making DIY warm boxes:

– Choose an appropriate plastic storage container or sturdy cardboard box. Look for a box that is about 2-3 times the size of the cat.

– Line the box with thick, insulating materials like straw, newspapers, or old towels and blankets. This padding helps hold in body heat.

– Cut a circular entrance hole on one side of the box and make sure air can still circulate from other openings.

– Consider extra weatherproofing like tarps or flap doors to protect from wind, rain, and snow.

– Place the box in a sheltered area and elevate it off the ground if possible.

Caring for community cats extends beyond just providing warm shelters. Be sure to also supply food and water, gain their trust, and monitor for any signs of illness or distress. With some simple materials and a bit of effort, we can help outdoor cats safely endure the winter months.

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