Why Does My Cat Sleep More in Summer?

You've noticed it. The sun comes out, the temperature creeps up, and your cat – already a committed advocate for horizontal living – somehow manages to sleep even more. You didn't think it was possible. And yet.

It's not laziness. Well. It's not only laziness. There's genuine science behind why cats become even more devoted to the art of doing nothing when the weather warms up.

Cats are warm-blooded animals, but they're not built for the kind of sustained heat regulation that humans are. They can't sweat through their skin the way we do – they rely mostly on panting, grooming and finding the coolest patch of floor in the house (which they will locate before you do, every time).

Regulating body temperature in the heat takes energy. Real energy. So cats do what makes complete biological sense: they conserve it. More sleep means less heat generated by the body, which means less work to stay cool.

Cats are crepuscular by nature, meaning they're wired to be most active at dawn and dusk when it's cooler. In summer, the hottest part of the day falls right in the middle – which is exactly when you'll find them completely comatose on the tiles, one leg hanging off the sofa, fully committed to being inert.

This is their natural instinct kicking in. Rest during the heat. Reserve energy for the cooler hours. It's the same logic big cats use in the wild, just with significantly less hunting and significantly more staring at a fly.

It's not just the amount of sleep that changes in summer – it's the quality too. Cats cycle between light dozing and deeper REM sleep, and in hot weather that balance can shift. When they're warm and uncomfortable, they tend to stay in lighter, more restless sleep rather than dropping into the deep restorative kind. Which explains why your cat can appear to have been asleep for four hours and still look absolutely shattered.

Think of it less as laziness and more as their body doing its best in conditions it wasn't entirely designed for. The more comfortable and cool they are, the better quality rest they actually get.

Want to help your stay cool this summer? We've got a full guide right here.

Almost certainly, yes. Cats sleep anywhere between 12 and 16 hours a day normally – and in a heatwave, that can nudge even higher. What you're looking for is the difference between a cat who is relaxed and resting versus one who seems genuinely unwell.

Signs it's just summer: loose, comfortable posture, easy to rouse, normal behaviour when they are awake, eating and drinking reasonably well.

Signs worth a vet call: real lethargy that doesn't lift in the cooler evening hours, loss of appetite for more than a day or two, hiding, panting heavily or seeming distressed.

For now, there's a good chance your cat is absolutely fine – just operating at peak summer efficiency. Horizontal. Unbothered. And probably on the one bit of floor you actually need to walk across.