From zoomies to zzzs: Why do cats sleep so much in summer?

October 11, 2023 - 3 min read
This article is not intended to be a substitute for professional veterinary advice, diagnosis, or treatment. Always seek the advice of your veterinarian with any questions you may have regarding your pet’s care, treatment, or medical conditions.
Amazing domestic bengal cat with spotted fur lying on sofa and smiling In her sleep. Cat's dreams.

When it’s time to chase a laser pointer or pounce on a rubber mouse, cats are all energy. But once they’ve found the sunniest spot in the house, good luck rousing them from their feline slumber, especially in the summer heat.

Do cats sleep more when it's hot?

On average, cats doze off for a whopping 13 to 16 hours per day.

These sustained snoozefests aren’t a sign of laziness but rather a reflection of cats' unique evolutionary biology and their individual health needs.

Read on to learn why these lengthy catnaps play a crucial role in your kitty’s overall well-being, particularly during the summer.

The biology behind cats' sleep patterns

Cats are obligate carnivores, meaning they need to get most of their nutrients from high-protein meats.

As a result, cats are some of the most skilled predators in the animal kingdom, a role they've perfected over millennia. (One study found that cats have contributed to the extinction of at least 2 reptile species, 21 mammal species, and 40 bird species, accounting for 26% of all known contemporary extinctions in these species groups!) 

Their meat-heavy diet plays a major role in their sleep patterns. After a protein-rich meal, cats often experience a surge of the amino acid tryptophan, which leads to the production of serotonin. This naturally occurring brain chemical serves as a mood stabilizer and brings about feelings of contentment and relaxation. This all sets the stage for a good snooze.

woman in white long sleeve shirt holding spoon full of cereal at table. Black and white cat eats off a small tray next to her on the table.

Cats’ ancestors were nocturnal hunters, a trait that modern-day domestic cats still exhibit, although to a lesser extent. The tendency to doze during daylight hours and become more active as dusk falls is a natural rhythm ingrained in their predatory DNA.

The sleep-wake cycle of cats is actually regulated by the same light-sensitive hormone, melatonin, that governs human sleep. But cats have a quicker sleep cycle, transitioning from deep sleep to REM sleep faster than humans. This allows them to be well-rested yet ready to spring into action at a moment's notice.

The importance of sleep for cats

Sleep is fundamental to your cat’s health and well-being. Here are some of its myriad functions:

Physical health

Sleep is crucial for your cat’s physical health on multiple levels:

  • Growth and Development: Especially in kittens, sleep is prime time for growth and development. It's primarily during the deep sleep phases that the body releases growth hormones.

  • Body Restoration: While it's known that cats are energetic creatures, play and hunting are often followed by rest periods, allowing their bodies to recover and prepare for the next burst.

  • Immune Function: Maintaining a robust immune system is one of the many benefits of good sleep. A well-rested cat is better positioned to fend off illnesses, contributing to a longer, healthier life.

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Mental health

Sleep is just as important for your kitty’s mental health, including:

  • Learning and Memory: Sleep is a crucial time for memory consolidation and learning in cats. It allows the brain to process new information and experiences, enhancing their cognitive health.

  • Stress Reduction: Good sleep can help alleviate stress and promote emotional stability in cats, ensuring they wake up calm and content.

Mother and son playing with cat at home

Cellular repair and maintenance

Sleep also serves as a kind of internal kitty tune-up.

  • Healing: The body enters a repair mode during sleep, mending the wear and tear from the day’s activities. This is when cell regeneration and repair processes are most active, aiding in quicker recovery from injuries.

  • Detoxification: Sleep serves as a detoxification period, facilitating the removal of waste products from various organs and ensuring a clean slate for the body to function efficiently.

Sleep is a cornerstone of a cat's holistic health. Each snooze session is a step towards maintaining their physical vigor and mental acuity. So the next time you see your feline friend curled up for a nap (especially on the floor in summer), remember: They’re just taking care of their overall well-being.

Factors affecting cats' sleep duration

Cats, like humans, have various factors influencing how much they sleep. 

  • Age: Kittens require more sleep for their growth and development, often snoozing for up to 20 hours a day. Similarly, as cats age, they tend to sleep more, often ranging between 16 to 20 hours a day, partly due to a decrease in energy and possibly due to health-related issues.

  • Activity Level:Active cats may sleep less compared to their less active counterparts. At the same time, regular exercise can also lead to deeper, more restorative sleep.

  • Diet: A well-balanced diet can contribute to better sleep quality and duration. Conversely, a poor diet might lead to sleep disruptions.

  • Environment: A comfortable and safe environment promotes better sleep. Cats prefer quiet, cozy, and secure places to sleep.

  • Household Routine: Cats are creatures of habit. A consistent routine in the household can lead to a more predictable sleep pattern.

  • Stress and Anxiety: Just like in humans, stress and anxiety can affect a cat’s sleep. Creating a stress-free environment can contribute to better sleep quality and duration.

Understanding the various factors affecting your cat's sleep can help you make sure they’re getting the rest they need. It all comes down to maintaining a comfortable sleep environment, a balanced diet, and regular check-ups to monitor their health.

Cat hunting to mouse at home, Burmese cat face before attack close-up. Portrait of funny domestic kitten plays indoor. Look of happy Burma cat preparing to jump. Eyes of playful pet wanting to pounce.

When should you be concerned about your cat's sleep habits?

While it's normal for cats to sleep for long hours, there are certain signs that might indicate a problem. Take note of any sudden changes in your cat's sleep pattern or behavior. Here are some signs that should prompt a visit to the vet:

  • Excessive Sleep: If your cat is sleeping more than 20 hours a day or seems lethargic when awake, it's worth a vet check to rule out underlying issues.

  • Restlessness: Conversely, if your cat is sleeping significantly less and seems restless or agitated, it could be a sign of discomfort or illness.

  • Change in Appetite: Changes in appetite, whether increased or decreased, alongside sleep changes, warrant your attention.

  • Behavioral Changes: Any abrupt change in behavior, mood, or interaction can be a sign of a health problem affecting their sleep.

  • Physical Symptoms: Noticeable weight loss or gain, changes in fur condition, or other physical symptoms alongside sleep changes should be investigated.

Why do cats sleep so much in summer?

Cats tend to sleep more in the summer due to the heat. The high temperatures can make them more lethargic, leading them to seek out cool, shaded areas to rest.

You may find your cat sleeping on the floor in summer because it's often cooler than other surfaces. Understanding this behavior can help you ensure your cat stays comfortable and healthy during the warmer months.

How cat insurance can help

Being observant and proactive in monitoring your cat’s sleep and overall behavior will help them stay healthy, especially if you promptly take any major concerns to the vet.

If your cat’s changing sleep habits are related to an underlying veterinary issue, cat insurance may help reimburse you for treatment.


David Teich
Lead Editor

David oversees content strategy and development at ManyPets. As Lead Editor, he focuses on delivering accurate information related to pet care and insurance. David’s editorial background spans more than a decade, including a pivotal role at Digiday, where he wrote content and managed relationships with media and tech companies. As an Associate Editor at Cynopsis Media, David wrote the Cynopsis Digital newsletter and interviewed executives and digital marketing experts in the TV industry. His background also includes film journalism. His diverse experiences in journalism and marketing underpins his role in shaping content within the pet care industry.