Why your cat loves the sun, and how to give them a sunny spot without overdoing it
Share
If your cat loves the sun, it is first of all for the warmth. A cat's body is comfortable between 30 and 38 °C, well above a heated living room, and a patch of sunlight gives them that extra warmth, especially during a nap. Not for vitamin D, which comes from the food bowl. The real risks are sunburn and summer heat.
Why do cats like the sun so much?
Cats like the sun because they need more warmth than we do. According to vet Aine Seavers, writing in the Veterinary Ireland Journal, a cat's thermoneutral zone, its comfort range, runs from 30 to 38 °C according to the US National Research Council, while we are comfortable between 18 and 25 °C. She notes that cats hog the windowsills to soak up the sun's heat through the glass.
Naps make that need stronger. According to a 2019 review in Frontiers in Neuroscience, in mammals, falling asleep goes hand in hand with a drop in core body temperature, and seeking out a warm spot is one of the behaviours that lead up to sleep, along with curling up. Hence the cat who follows the light from room to room.
Where can a flat cat find a sunny spot?
In a flat, the sunny spot is almost always the window. Your cat still needs room to stretch out there, and a windowsill is rarely deep enough.
The Pelux cat window perch solves that: a 55 × 35 cm seat in Oxford fabric, hung against the glass on steel cables and attached with four suction cups 8 cm across, with no drilling. Its conditions, according to the supplier:
- A smooth, clean pane, single or double glazed, where all four suction cups fit together; a wall will not do. A window divided into small panes may not offer enough surface: check the size of the glass.
- Careful fitting: suction cups soaked in lukewarm water, glass cleaned, pressed in firmly, then 10 minutes' wait before your cat gets on.
- 17.5 kg at most, provided all four suction cups grip well: check them from time to time.
In winter, the low sun reaches deep into the room: that is the season for this spot.
A sunny spot of their own, against the glass
Your cat stretches out across the whole seat instead of curling up tight on the edge of the window, and the perch holds to the glass without a single hole. Discover this suction-cup perch →
Do cats get vitamin D from the sun?
No: unlike us, cats do not make enough vitamin D through their skin. That is the conclusion of a study published in 1994 in General and Comparative Endocrinology, carried out on skin samples: cat skin holds little of the vitamin D3 precursor, and UVB light does not raise vitamin D3 in it, whereas it rises fortyfold in rat skin. The authors conclude that cats depend on their diet.
For a cat fed a complete diet, then, the sun is not a vitamin D matter; only your vet can judge a deficiency. At the window, your cat is after warmth, and another gentle heat source can provide it.
White cats, pale ears, hairless cats: is the sun dangerous?
Yes, for these cats, even indoors. According to Cats Protection, the UK cat welfare charity, the cats most at risk of sunburn are white or pale cats, cats with white ears, hairless cats and those with a thin coat; the edges of the ears are most often affected, then the nose; repeated, the exposure raises the risk of skin cancer, including squamous cell carcinoma.
Glass is not enough: according to Cats Protection, even an indoor cat can get sunburnt if they sleep for long spells in direct sunshine by a window. The charity advises drawing the curtains in sunny rooms during the hottest hours. Aine Seavers adds that keeping such a cat away from windows is not enough: without a source of warmth indoors, they will go looking for the sun regardless.
| Cat profile | In the sun, behind glass | What helps |
|---|---|---|
| Dark coat, healthy adult | A favourite spot, especially in winter | A shady corner to retreat to, curtains drawn in summer |
| White cat or pale ears | Not hours in full sun | Your vet's advice, shade in the hottest hours |
| Hairless cat | Skin exposed with no fur to filter | Your vet's advice, warmth without sun |
For these cats, the window perch is not the answer on a south-facing window. Ask your vet first; if they would rather your cat had warmth without sun, a cosy bed away from the glass, in our beds and scratchers range, will do better. Pink, flaking skin, scabs, sores: see your vet. For the season's other risks, read our guide to summer dangers for cats.
Summer, when the window gets too hot
In summer, a south-facing window becomes a heat trap in the afternoon, as our article on cat beds through the seasons points out.
The rule: your cat must always be able to leave the spot for somewhere cooler. In the hottest hours, lower the shutter or blind, and keep fresh water within reach.
Look at where your cat already lies on hot days: the hall tiles, a corner of parquet. That is where the Pelux cat cooling mat belongs, cool to the touch, with no gel and no electricity. It does not produce cold, and replaces neither water nor shade in a heatwave.
If your cat pants or goes limp in the heat, call your vet: our article on heatstroke in cats sets out the signs.
Frequently asked questions
My cat seeks the sun far more than before: should I worry?
Mention it to your vet. According to Aine Seavers, a cat that cannot settle and keeps seeking warmth may be in pain: in some arthritic cats, warmth brings relief, but the pain needs treating too. For an older cat, see our article on beds for senior cats. If it comes with a loss of appetite or listlessness, see your vet without delay.
Can you put sun cream on a cat?
Only if your vet recommends it, and only a product made for pets. Cats Protection warns never to use human sun cream on a cat: it may contain ingredients that are toxic to them.
Is the window perch suitable for a large cat?
The supplier states a maximum load of 17.5 kg, confirmed in writing, for suction cups properly fitted to a smooth, clean pane. Then there is space: measure your cat stretched out full length and compare with the 55 × 35 cm seat.
Key points
- Cats love the sun for its warmth: their comfort zone runs from 30 to 38 °C, and their core temperature drops as they fall asleep.
- The sun does not give cats vitamin D: their skin does not make enough of it, and their diet provides it.
- A white, pale-eared or hairless cat should not spend hours in full sun, even behind glass: your vet's advice comes first.
- A south-facing window, ideal in winter, gets too hot in summer: your cat must always be able to leave it for a cool corner and water.