Do Cats Need Sun? Three Reasons Why They Do

Do cats need sun? Well, yes and no. Cats don’t need sunlight for vitamin D. We get that from our food. But cats do need sunlight to help keep our body temperatures regulated and conserve energy. We need it to feel warm, cozy and secure, too.  


Do cats need sun to be healthy? Not really. But like this cat, they love nothing more than a nap in a sunny spot.

Cats love nothing more than a nap in a sunny spot.

Do cats need sun to be healthy, Thomasina? I like to keep my blinds and curtains closed. But I’m afraid I’m harming my cat.

— Worried Cat Mom

Hey, Worried Cat Mom!

I wouldn’t worry about your cat. Cats need sun, but not to be healthy.

That said, could you leave just one blind or curtain open? Cats like to lie in the sun. That’s one of our all-time favorite things to do!

Do Cats Need Sun? Yes, But Not For Vitamin D

Cats need vitamin D to keep our immune systems functioning well, help with recovery, reduce inflammation and aid in absorbing calcium. It’s also important for bone growth. 

But unlike humans, cats don’t absorb vitamin D through our skin. We might get a tiny bit if we’re lying in the sun and lick some off our fur. But the amount of vitamin D we need to stay healthy comes from our food. If you feed commercial cat food or follow a recipe to make homemade or raw, your cat should be getting the right amount. Just check the ingredients to be sure.

Be careful, too. Too much vitamin D can make cats really sick. If you’re sure your cat is getting the right amount in her food, adding a vitamin D supplement can be very dangerous.

The main cause of vitamin D toxicity in cats is rodent poison. But supplements are right up there, too. Check this list to see the signs of vitamin D poisoning in cats.  

Three Reasons Why Cats Like To Lie In The Sun

Cats like to lie in the sun because it feels warm, cozy and secure. There’s nothing more luxurious than stretching out for a nap in a patch of sunlight.

But there are two other reasons why we love lying in the sunlight, too. 

The first is that sleeping in the sun can help us regulate our body temperatures, which are higher than yours. Your normal body temperature is 98.6 degrees. Ours is 102.5 degrees. So if you set the thermostat at 70-80 degrees, that feels a bit chilly to us. A sunny spot can help us keep our body temperature where it’s supposed to be.

Conserving energy is another reason why we like to lie in the sun. Our metabolism (What the heck is that??? My human typist added it) slows way down when we’re sleeping. The sunlight helps us store energy that we’ll need when we’re awake and ready to run and hunt.

Compromising With Your Cat

Do you think you could compromise with your cat and leave just one blind or curtain open? It doesn’t have to be open all the way. Just enough for him to get some sun and see outside will work. He’ll be so grateful, and he’ll feel so much happier.

You could even get him a window perch  and a bird feeder to hang on the window. He’d love those!

I hope this helps, Worried Cat Mom. If you’ll excuse me, I have to get on my way now. The sun’s shining in my favorite spot in the living room, and I need a nap!


















Thomasina believes she’s uniquely qualified to answer questions about cats. “It takes one to know one,” she says. Read more about Thomasina.

Browse By Topic

 Freelance Writing

Well, no, I won’t! But my human typist can do blog posts about cats for your vet clinic, grooming shop or pet supply store. She’s a good writer, too! Contact her at

 About Our Ads

We have an affiliate relationship with Google, and other retailers. The small commission we earn from click-throughs and purchases keeps this blog running and the cats fed.

Why Do Cats Pull Food Out Of The Bowl? Not Because They’re Sloppy!

Cats pull food out of the bowl for a reason, and it’s not because we’re sloppy! If your cat eats off the floor, he might be eating the way instinct tells him to. And there are other reasons why some cats eat off the floor, too. 

Why do cats pull food out of the bowl? Sometimes it's because they don't have whisker friendly bowls like this one.

This cat is enjoying his food from a whisker friendly bowl.

Why do cats pull food out of the bowl and eat it off the floor, Thomasina? My cat makes such a mess!
— Frustrated

Hi, Frustrated!
Yikes!! I’m sorry about the mess. Although I don’t do it, I can think of a few reasons why cats pull food out of the bowl.

Why Some Cats Pull Food Out Of The Bowl: It’s All About Instinct

6 Reasons Why Cats Mat | How To Unsnarl Tangled Fur

It’s not just long-haired cats who get mats. Cats with short hair do, too. Cats mat when the weather’s changing. But keep a close eye on your cat with matted fur. Mats can also be a sign of health problems. 

Cats mat for a variety of reasons, but brushing can help prevent tangled fur.

Cats mat for a variety of reasons, but brushing can help prevent tangled fur.

Why do cats get mats, Thomasina? My elderly cat is just one big tangle. She’s a mess!

— Sad Cat Mom

Hi Sad Cat Mom!

That’s a great question. I have a huge mat right now! For me, that must mean the seasons are changing. But there are other reasons why cats mat, too.

Shedding Causes Matted Cat Hair

Cats In Cold Weather | How They Cope

Personally, I prefer to be inside when it’s very cold. But cats in cold weather can be just fine, especially if they have some help from humans. We have all kinds of ways to cope with cold weather, and some of them might surprise you!

Cats cope with cold weather in many ways, but one of them isn't wearing a muffler!

Cats cope with cold weather in many ways, but one of them isn’t wearing a muffler!

I worry about outside cats in cold weather, Thomasina. it sounds like you spend a lot of time outdoors, and I’m really concerned about you.
— Worried

Hi, Worried!

Thanks for your concern. Don’t worry about me. Cats cope with cold weather in all kinds of ways, and I’m just fine! I love being outside, and since I’m outdoors so much, my body has plenty of time to acclimate to the changing seasons. I have my winter conditioning now. And if I get too cold, I can always go inside. That’s where I am right now!

The Ways Cats Cope With Cold Weather

Are Cats Smart? Five Ways To Find Out

Are cats smart? I have to admit I know one who seems dumb as a rock. But most of us are very smart, although not in the same ways you are. We couldn’t do a complicated math problem, but I’ll bet you couldn’t figure out how to catch a mouse!

Are cats smart? Most are, although they'll never earn a diploma

Maybe your cats will never earn diplomas. But that doesn’t mean they’re not very smart.

Are cats smart Thomasina? Mine does the dumbest things!  — Curious Cat Mom

Hi Curious Cat Mom!

I’ll bet some of the things your cat does that seem dumb to you make perfect sense to him. Most cats are smart — very smart. But we use our intelligence in different ways than you do because we need to accomplish different things.

Although your cat can probably count exactly how many treats you just gave him, we have no need to understand advanced math. And you have no need to know how to catch a mouse because you probably wouldn’t eat one, no matter how hungry you were. 

Cats Have Lots Of Brain Power Packed Into A Tiny Package

How Do Cats Know What Time It Is?

Do cats know what time it is? We do! We come with built-in clocks that tell us what we need to do when. They’re really handy when it’s time for breakfast!

Somehow cats know what time it is, and they don't need to look at a clock.

Your cat doesn’t need a clock to know what time it is.

How do cats know what time it is, Thomasina? My indoor/outdoor cat comes in every night promptly at 10 pm. If I open the door a bit early, he’s not there. But if I’m a few minutes late, he’s annoyed because he had to wait. Does he really know what time it is?
— Just Wondering 

Hi Just Wondering…

Cats know what time it is, although we don’t think of it the way you do. You look at time in minutes and hours. We see it in intervals.

Our sense of time is based on circadian rhythms (On what??? My human typist stuck that in there) that pretty much control our internal clocks. Those clocks tell us when one interval (being outside) should end and another (going in for a nap) should begin.

It sounds like your cat’s clock is set to tell him to go inside at 10 pm your time. Of course, he might decide to reset the clock, depending on the weather. So don’t be surprised if his schedule changes with the seasons.

The Sun Helps Cats Know What Time It Is