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Do Guinea Pigs Need Sunlight? Vet Reviewed Facts & FAQ


Mar 23, 2023
silkie guinea pig


silkie guinea pig
Dr. Lorna Whittemore Photo

The information is current and up-to-date in accordance with the latest veterinarian research.

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When caring for a guinea pig, most owners would think about the common things they need, such as food, water, hygiene, cleanliness of the environment, and much more. An important thing to consider when caring for guinea pigs is the amount of natural light they are exposed to. Do Guinea pigs need sunlight? The simple answer is yes! Exposure to sunlight is needed for a guinea pig’s overall health.

But that doesn’t mean a guinea pig should just be placed outside on a warm, sunny day. There are certain things to consider when exposing your guinea pig to sunlight. Below, we discuss how to properly expose your guinea pig to sunlight, and how it benefits your guinea pig!


Why Do Guinea Pigs Need Sunlight?

Guinea pigs need sunlight just as much as they need food and water! For guinea pigs, sunlight helps them produce vitamin D.1 Guinea pigs need vitamin D for healthy skin and bones, they need vitamin D in their diet and exposure to UVB.

Sunlight is also beneficial to guinea pigs as sunlight in the daytime helps stimulate activity. Guinea pigs sleep in the dark, so exposure to sunlight promotes movement, digestion, and overall health for your guinea pig.

While your guinea pig can obtain their nutritional requirements through a healthy diet, proper hydration, and ample exercise, it won’t be enough unless they receive enough sunlight exposure for vitamin D. Lack of sunlight exposure can even lead to weakness or sickness, further highlighting how important sunlight is to guinea pigs.

How Much Sunlight Do Guinea Pigs Need?

guinea pig hiding
Image Credit: Jumpstory

While sunlight is important for a guinea pig’s health, too much sunlight can be harmful and put them at risk of sunburn, overheating, and even vitamin depletion. To obtain the benefits they need, indirect sunlight is enough!

When exposing your guinea pig to sunlight, moderation is key. Guinea pigs prefer shaded or filtered light. When exposed to excess sunlight, you will often find them seeking shade to escape the heat, they are not very heat tolerant and can develop heat stroke.

Should you decide to take your guinea pig outside for some sun, it is best to do it during the dimmer parts of the day, such as early morning or later afternoon when the sun is either rising or setting. The sunlight won’t be too intense and the temperature won’t be too high, which is what guinea pigs prefer!

Indirect sources of sunlight, such as lamps and indoor light sources can also be used, but be sure to control how much exposure they get as the temperature from these light sources are much more difficult to manipulate.


Why Are Guinea Pigs Sensitive to Sunlight?

To understand why guinea pigs are so sensitive to sunlight, we have to look at how their bodies work, as well as their natural instincts and behavior.

Guinea Pigs’ Body Temperature

Two Guinea pigs under the rocks
Image Credit: Petra, Pixabay

A guinea pig’s body temperature is a huge factor as to why they are so sensitive to sunlight. They have a body temperature of 102° to 104° F (39° to 40° C), which is higher than the normal body temperature of humans. This higher body temperature makes guinea pigs extremely sensitive to changes in temperature, which can be brought about by direct sunlight.

When experiencing heat, humans sweat to regulate their body temperature. Unfortunately, guinea pigs are unable to sweat, which puts them at risk for dehydration and overheating. Guinea pigs rely on their environment to regulate their body temperature.

When these piggies feel cold, their blood vessels constrict to divert their blood to the torso to keep them warm. When they experience heat, their blood vessels dilate to transfer heat out of the body through convection. This is why piggies would actively look for water, shade, or a cool place to rest when they feel hot in order to cool down.

To keep them comfortable, an ambient temperature of 60°–85° F (15.5°C–29.4° C) is recommended.

The Crepuscular Guinea Pig

Guinea pigs are crepuscular animals, meaning they are most active during the twilight periods of the day. Guinea pigs are naturally more active during dawn and dusk, when the sunlight is dim, and the temperature is relatively cool. Low light means low temperature, making it the optimal environment for them to receive natural sunlight!

Aside from the physical effects that these piggies can experience during the twilight hours of the day, this crepuscular behavior is also influenced by their survival instincts. When moving during the twilight hours, guinea pigs are less likely to be eaten by predators! Most predators are either nocturnal or diurnal, meaning they hunt during the night or the day, making the twilight hours a great time for guinea pigs to move while avoiding being hunted!

How to Safely Provide Sunlight to Your Guinea Pig

Two guinea pigs on the grass
Image Credit: Charleen Magne, Shutterstock

One common challenge for guinea pig owners is figuring out how to let your guinea pig receive sunlight without overheating. Below are some tips on how to properly expose your guinea pig to natural sunlight!

  • Take your guinea pigs out during times of the day when sunlight is not at its peak.
  • Make sure they have areas with shade to help them cool down.
  • Ensure they have access to water.
  • Do not leave your piggies unsupervised.
  • Place your guinea pig’s cage in an area with indirect sunlight.
  • Artificial light sources, such as UVB lamps, are recommended when sunlight is scarce.
  • Read your piggy’s behavior. If they seem like they are constantly looking for shade, it means that they’ve had enough sunlight for the day!

Signs of Overheating

Guinea pigs are sensitive to heat because of their high body temperature and inability to regulate their temperature easily. Overexposing your piggies to sunlight or heat unattended can lead to overheating, and it is important to look out for the signs, such as:

  • Panting
  • Weakness and lethargy
  • Excess drooling
  • Inability to move
  • Bright red tongue
  • Convulsing

Guinea pigs rely on their environment to cool off. To bring down their temperature, rinse them in cool water and contact your local veterinarian for medical management.



Guinea pigs need indirect sunlight just as much as they need a healthy diet and proper hydration. With sunlight and the correct diet, they are able to produce enough vitamin D, which promotes healthy skin and bones.

Because guinea pigs are sensitive to changes in temperature, they are prone to overheating if exposed to too much sunlight and heat. To keep your guinea pig healthy, happy, and active, let them experience sunlight during the cooler times of the day!

Featured Image Credit: Linn Currie, Shutterstock

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