Corn Snake Temperatures, Lighting & Humidity

corn snake lighting and UVB

Lighting

Because corn snakes are most active around nighttime, many say that lighting beyond the natural cycle of the lights in your house/reptile room is not required. This is incorrect. Just as there is bright daylight in the wild, corn snakes need a distinct day/night cycle in captivity as well.  Providing terrarium-specific lighting is very beneficial for regulating your snake’s natural biorhythms and encouraging natural behaviors.

Simply speaking, your corn snake’s lights should be on 12 hours/day. If you want to create a more natural day/night cycle for your pet, try a graduated cycle of 13 hours of light during summer and 11 hours during winter. Providing a seasonal light cycle can help promote more natural hormonal rhythms in your snake, resulting in better overall health.

Do corn snakes need UVB?

Wild corn snakes are sometimes exposed to varying levels of UVB wavelengths during the day. Conventional wisdom dictates that UVB is not required for most snakes, and it’s true that they can live without it, as has been proven by years of captive breeding. BUT  — recent studies (especially work by Frances Baines) increasingly suggest that UVB can be very beneficial for a snake’s mental and physical health. This goes beyond the requirements of survival and is part of ensuring that the animal thrives in captivity. In fact, Does exposure to UVB light influence the growth rates and behaviour of hatchling Corn Snakes, Pantherophis guttatus? outright recommends using UVB lighting for captive corn snakes, and it can be easily argued that UVB provision is also required to comply with Mellor’s 5 provisions of animal welfare in captivity.

We at ReptiFiles strongly recommend providing UVB to all pet reptiles, including corn snakes. To include UVB in your husbandry, use a T5 HO UVB fluorescent tube like the 22″ Zoo Med Reptisun T5 HO 5.0 or 22″ Arcadia Forest 6% and replace every 12 months. We strongly recommend avoiding other brands/types of UVB bulbs. We specifically recommend Zoo Med and Arcadia because other brands have proven to be unreliable and even unsafe.

How to Install UVB for Corn Snakes:

The strength of UVB that a reptile is exposed to depends on its distance from the bulb, so it’s very important to take distance into consideration when you’re installing the basking area. Assuming that the fixture is placed over mesh to prevent direct contact between the snake and bulb, the mesh will cause a ~40% reduction in the bulb’s output. This means that the basking area should be placed about 7-9″ below the lamp for safe, effective use.

If at all possible, we also recommend investing in a Solarmeter 6.5 to track your UVB bulb’s output at the basking site. As a low-UV species, corn snakes should have a UVI of 2.0-3.0 in the basking area, which should be the area of highest temperature and UV in the enclosure.

  • PRO TIP: If you use UVB, make sure that the fixture doesn’t have a piece of glass or plastic to “protect” the bulb. UVB rays are blocked by glass and plastic, rendering that bulb you just spent so much money on completely useless. Naked UVB bulbs are effective UVB bulbs! 

Do corn snakes need a night light?

Nighttime lighting such as a colored bulb is not necessary. At best, it is likely to disrupt your snake’s circadian rhythm (day/night cycle). At worst, it may damage your snake’s eyesight and/or mental health. In other words: Don’t waste your money. 

Heating

Corn snakes are reptiles, which means that they are ectothermic, or cold-blooded. Ectotherms rely on their environment to provide the heat energy that their bodies need for proper metabolism. Reptiles that do not have access to enough high-quality heat are likely to experience problems like low energy, susceptibility to illness, and slow healing.

Perfect corn snake temperatures occur on a gradient, with 3 temperature zones across the terrarium. This enables to the snake to move between zones as is comfortable. Here’s the parameters you need to pay the most attention to:

  • Basking surface: 90°F (32°C)
  • Ambient (air temp): 78-82°F (25-27°C)
  • Cool zone: 75°F (23-24°C)

Temps can safely fall to 68°F (20°C) at night, so night heat should be not be necessary. However, if you do need it, use a ceramic heat emitter or heat pad connected to a thermostat. The thermostat is required for safety — it is not optional!

I recommend spending a quick $20 on a good infrared thermometer like the Etekcity Lasergrip 774 for instant temperature readings anywhere you point it. (Don’t bother with a sticker or gauge-type thermometer — they’re useless.) 

This is one of the big reasons why it is important to set up your enclosure at least a week before bringing your corn snake home — getting corn snake temperatures in the right place can take some fiddling around, especially since different heat bulb wattages produce different temperature depending on a variety of factors such as enclosure height and room temperature.

How to Heat Your Corn Snake’s Enclosure:

Heat is a type of energy called infrared. Infrared is invisible to humans and most reptiles (certain snakes being the exception). Just like there’s different types of ultraviolet light, there are also different types of infrared: IR-A, IR-B, and IR-C.

  • IR-A is the strongest wavelength of infrared. It is capable of penetrating deepest into animal tissues, making it particularly effective at delivering energy to ectotherms like reptiles. It also has healing properties and is used clinically as a form of therapy. IR-A is present in large quantities in sunlight.
  • IR-B is the second-strongest wavelength of infrared. It penetrates less deeply than IR-A, and is less effective, but can still be considered “high-quality” heat. IR-B is also present in significant quantities in sunlight.
  • IR-C is the weakest wavelength of infrared. It doesn’t penetrate past the skin, making it the least efficient source of heat for basking. It is present in very small quantities in sunlight, and is more often experienced as radiant heat from sun-warmed objects like rocks and asphalt.

The goal of providing heat in a reptile’s enclosure is to imitate the forms of heat it would experience in the wild as accurately as possible. For more information, I recommend reading Next Level Heating: Why Infrared Wavelengths Matter by Roman Muryn.

BEST: Heat Lamps

In nature, warmth comes from the sun (above), not from the ground (below). In fact, reptiles retreat underground to escape the sun and get cooler, not warmer. Providing warmth from below, as with a heat mat, is therefore unnatural and will promote unnatural behaviors. Heat lamps solve this problem by mimicking the effects of the sun and warming both the air and the ground below.

Of course, there are several different types of heat lamps:

  • Halogen and “incandescent” heat bulbs produce primarily IR-A and IR-B.
  • Deep heat projectors and other carbon-filament bulbs produce primarily IR-B and IR-C.
  • Ceramic heat emitters produce primarily IR-C.

Considering that the goal is to replicate sunlight as the primary source of heat in a corn snake’s environment, we recommend using halogen flood heat bulbs as the most effective method of providing heat to your corn snake. There are many different types of heat bulbs on the market, from reptile-specific brands to ordinary bulbs at your local home improvement store. Reptile brand halogen bulbs can work well, but they tend to be short-lived. Personally, I’ve had the best experience with the 90w Philips Halogen PAR38 Flood bulb

For best results, get 2 bulbs and mount them in a Zoo Med Mini Combo Deep Dome fixture or two 5.5″ dome lamps. For safety reasons, the bulb socket must be ceramic, not plastic. I also recommend getting a couple of plug-in lamp dimmers like the Lutron Credenza so you can dim the bulbs if they get too hot. Alternatively, you can invest in a proportional (dimming) thermostat like the Herpstat 2 which will do that for you automatically.

Place the heat lamps above the basking surface, which should be the same thick branch that will be placed under the UVB lamp. I recommend using two heat bulbs instead of just one because this facilitates more even heating over your snake’s body, which is better for its circulation and overall health. Using one bulb won’t be a problem when your snake is just a juvenile, but as it grows, this becomes an issue.

If you are concerned about “belly heat,” here’s some good news: the branch will naturally absorb warmth from the heat lamp, warming the snake from below when it sits on it.

GOOD: Heat Mats

Heat mats are the still the most widely used method of heating corn snakes. Although they have been proven to be effective at keeping the snakes alive and reproducing, they’re not optimal. Heat mats produce only IR-C, the weakest form of heat, which results in inefficient basking. The snakes have to lay on the mats for long periods of time to gather the heat energy that they need. Plus, they do little to heat the air inside the enclosure. For these reasons, I don’t recommend using a heat mat as your snake’s primary source of heat.

However, heat mats can make a good secondary source of heat. When connected to a thermostat for safety and programmed to basking temperature, they can be used to create a lovely warm hideout for your snake, comparable to a sun-warmed burrow in the wild.

To do this, choose a high-quality heat mat roughly the same size as your snake’s warm hide. Trusted heat mat brands include Fluker’s and Ultratherm. Place the mat under the hide, covered by about 2″ of substrate. Then plug the mat into a thermostat and place the thermostat probe inside of the hide, on top of the substrate. Check the probe placement regularly.

Heat mats can only be safely used if paired with a thermostat, a device which regulates how hot the mat gets. Even if the heat mat claims to not need a thermostat because it only gets to a certain advertised temperature, believe me — it still needs a thermostat. Many a snake has been cooked to death by heat mat malfunctions!

Thermostats range in quality and price (lower price usually means lower quality). Herpstat is the best and most reliable, but if you’re on a tight budget, Inkbird and the Exo Terra Thermostat are low-cost options. Make sure to buy a thermostat appropriately rated for your heat mat’s wattage.

DO NOT USE HEAT ROCKS!

Heat rocks (also known as hot rocks/rock heaters/etc.) are manufactured and distributed under the same premise as an electric blanket — convenient heat whenever your reptile needs it. Sounds like a great idea, right? However, heat rocks are notoriously unreliable, and many a reptile has lost its life due to severe burns caused by these devices. Additionally, they’re not a good choice for heating your enclosure, as it only warms the rock’s surface, not the surrounding air.

Humidity

Corn snakes thrive between an average humidity of 65-75%. Correct humidity levels help prevent dehydration, maintain respiratory health, and facilitate proper shedding.

Most corn snake care sources assert that corn snakes will do fine somewhere between 40-60%, but after checking the annual average relative humidity for several different locations throughout confirmed corn snake territory, it became clear that they actually prefer areas of higher humidity than conventional “wisdom” suggests.

This means that you will likely not be able to maintain correct humidity levels with just a thick layer of humidity-friendly substrate and a large water bowl. Here are some tips to help you maintain healthy humidity levels in your corn snake’s enclosure:

  • Use moisture-retentive substrate. That means dry substrates like aspen and lignocel are out. 
  • Provide a layer of clean, chemical-free leaf litter on top of the substrate. Leaf litter is great at helping retain humidity, and also gives your snake something to explore.
  • Mist the enclosure daily. Wet things down first thing in the morning, then again at night if needed. Using a traditional spray bottle can give you hand cramps, so use a pressure sprayer like the Exo Terra Pressure Sprayer to make life a lot easier. 
  • Install a cool mist humidifier/fogger. For best results, only run it at night, scheduling it to run in short bursts rather than constantly. Make sure to only use distilled water, and clean the entire unit at least 1x/week with F10SC, Clean Break, or Rescue veterinary disinfectant to prevent bacterial growth.

It’s also a good idea to provide a humid hide for your snake to use as needed. Simply line a hide box/cave with moistened sphagnum moss and replace the moss regularly to prevent mold accumulation.

Don’t leave your humidity to chance — keep track of your corn snake humidity levels with a hygrometer! My personal favorite is the Zoo Med Digital Thermometer and Humidity Gauge. Place the probe in the middle of the enclosure to get an ideal of the enclosure’s average humidity.

It is normal for humidity to rise at night and drop during the day. Humidity will also be higher further away from the heat lamp than closer to it. Occasional fluctuations higher or lower than the given range are acceptable.

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