Why Do Cats Love Sunbathing? Warmth, Vitamin D Myths and Safety

By Tailwisp Editorial TeamUpdated October 20, 20264 min read

Every cat owner knows the sight of a cat stretched out on a warm patch of floor, soaking up a sunbeam. Cats chase sunlight around the house through the day. It looks like perfect contentment, and in many ways it is. But there are myths and risks too.

Why cats love the sun

Warmth. A cat's comfortable temperature is higher than ours, roughly 86 to 97 degrees Fahrenheit. Basking helps cats reach it without using energy.

Energy saving. Cats sleep a lot, and warmth reduces the energy needed to keep the body warm.

Muscle comfort. Heat soothes stiff muscles and joints, which is why older cats seek sun. See arthritis in cats.

Relaxation. The warmth and light are soothing.

Scent and surfaces. Sun-warmed fabrics and floors smell and feel good.

Instinct. In the wild, cats used sunny spots for warmth after nights of hunting.

The vitamin D myth

People make vitamin D in their skin from sunlight. Cats cannot do this effectively, because their skin lacks the necessary precursor. They get vitamin D from their diet, such as meat, so sunbathing is not a nutritional need. A complete cat food contains the required nutrients. See how to read a cat food label.

Sunbathing through glass

Window glass blocks most UVB, but not all UVA. Cats can still get warm, and some sunburn is possible through glass on very sunny days, though the risk is low. Heat can build up, so watch the room temperature.

Sunburn and skin cancer

White cats, and cats with thin or light fur on ears, noses and eyelids, are at risk of sunburn. Repeated sunburn can lead to squamous cell carcinoma, a skin cancer common in white cats. Signs include scabs, redness or sores that do not heal on the ears or nose. See cancer in cats and white cats and deafness. Limit midday sun, provide shade and ask your vet about pet-safe sun protection. Do not use human sunscreen with zinc oxide.

Overheating

Cats can overheat in hot, enclosed spaces, such as sunny rooms, conservatories and cars. See summer safety for cats and keeping cats cool in hot weather. Signs include panting, drooling and restlessness. Provide shade and water.

Safe sun time

• Give your cat a perch by a sunny window. See window perches and bird feeders.
• Keep windows secure, with screens.
• Provide shade nearby.
• Offer fresh water.
• Watch for heat in the afternoon.
• Move the cat if the room becomes too hot.
• Check ears and nose for redness, especially in white cats.

Outdoor sun time

If your cat goes out, provide shaded areas. A catio with a roof offers sun and shade. See how to build a catio.

Seniors and sun

Older cats benefit from warm spots, but they may not move away from heat. Check them. See senior cat care guide.

Black cats

Black fur absorbs heat, and cats with black coats may turn rusty. See black cats.

Heat lamps and heating pads

Use pet-safe heating pads, and avoid heat lamps that can burn. See how to choose a cat bed.

Sunbathing and the senses

Warm light stimulates a cat's relaxation, and sunny spots often carry interesting smells from sun-warmed fabric and dust. Cats also like the changing light patterns, and the movement of birds or insects in the sun. A cat that moves with the sunbeam across the floor is simply following comfort. You can encourage this by leaving a soft blanket or cat bed in the sun. Watch for signs that the cat is getting too warm, such as panting or restlessness.

Sunbathing and age

Kittens and young cats sunbathe, but older cats seem to seek the sun even more. They feel the cold more, and warmth eases stiff joints. If you have a senior cat, offer a soft, supportive bed in a sunny spot, and make sure it can get in and out easily. Check the room is not too hot, and that your cat can move away to a cooler place. See senior cat home modifications.

Sun spots and skin checks

While your cat basks, take a moment to check its skin and coat. Look for scabs, redness or new lumps on the ears and nose, and ask your vet about any that do not heal.

When to see a vet

See a vet if you notice red, scabbed or sore skin on the ears or nose. Use the US vet directory to find a clinic.