Argentine Tegu Temperature, Lighting, And Humidity Level Guide

Tegu temperature ranges

One of the most intimidating concerns that potential Argentine tegu owners have is getting the proper temperature, humidity, and lighting for for their tegu. These impressive large lizards require large enclosures. Because of this getting the temperature and humidity right throughout its enclosure requires a bit of planning. Though we will cover all of these concerns let’s start with the basics on the ideal tegu temperature ranges. 

The ideal temperature for an Argentine is 75-85 degrees on the cooler side of the enclosure and around 90-95 degrees on the warmer end.  Argentine Tegus also require a basking area that ranges between 100-130 degrees Fahrenheit. Proper temperature is vital for the lizards to regulate their core temperatures, digest food, and metabolize vitamins and minerals.

These lizards are savannah and grassland dwellers, so they like it the most where the sun is shining and warm. They are a hardy species and can tolerate some cooler temperatures, but it is not something they seek out. To learn more about the temperature tolerances of these quirky, large lizards, read on. 

Tegu Daytime Temperatures

While tegus can tolerate some cooler temps, too much exposure to temperatures below their optimal parameters will make them ill. Though Argentine tegus may be able to regulate their core temperature (as pointed out by NewScientist), we should always keep them within their acceptable range. 

Daytime temperature is the temp that a tegu’s enclosure should be kept during the day, mimicking their natural environments’ sunlight and temperatures. The cooler side of the cage should stay around 75-85 degrees and the warmer side should stay around 90-95 degrees. 

Tegus, do well if their enclosure is set up with a temperature gradient. By creating different temperature zones in their enclosure, the lizard needs only to move to a colder or warmer zone to regulate temperature. 

Since they can get too warm from relaxing in the heat, a cooler respite can make them very happy. That can be done simply in a few ways:

  • Create a gradient by adjusting heating elements
  • Create a cool hide
  • Give your tegu a pool

Tegus Need A Gradient Of Temperatures

The first and easiest way to get a proper temperature gradient in an enclosure simply requires a bit of trial and error. With a thermometer on one end of the enclosure, all you need to do is move around the heating and lighting elements.

By shifting the focus of heating and light towards one side of the enclosure, you can make the other end a bit cooler by about 5 -10 degrees. You’ll likely have to move things around to get the right temps in the right spots. And, you can always adjust based on where your pet likes to lay. 

Create A Cool Hide Of The Enclosure

A cool hide is just that; a place that your Tegu can hide in that is also a cooler temperature than the surrounding area. All it needs to be is a large enough space for them to crawl into and get out of the light and heat. Think of it as a tiny cave for your tiny dragon. Something as simple as a wooden box works well. Or, as you can, you can go the DIY route and build them a cool-looking faux-rock cavern. There are also many hides to purchase online or from your local pet shop. 

Give Your Tegu A Pool To Cool Off In

Some Black and White Argentine tegus like to get wet, soaking in water for hours at a time. Others, not so much. These lizards vary a lot in personality and preference. You can try giving your Tegu a larger container of water large enough that they can take a soak when they’re feeling too hot. 

Tegu Nighttime Temperatures

In the daytime, tegus like it nice and warm, but to create an environment that best mimics their natural habitat, it should get a bit cooler at night— around 5 to 10 degrees cooler from daytime temps. You shouldn’t go any lower than 65 degrees at any time. 

We’re not talking about turning all heat sources off come nightfall. That would likely be too cold for you, scaly pal. You’ll still need to keep your heat sources operating throughout the night, especially if you live in a colder area. 

You can turn the lights off at night. Still, you’ll need to supplement with additional heat via ceramic heaters, infrared heaters, or even a space heater to keep the entire room at a suitable ambient temperature.

There are also special nighttime bulbs that glow dimly without UVB radiation but still produce heat. These allow you to view your Tegu still after the sun goes down, but they won’t mess with the reptile’s circadian rhythm. 

Ideal Tegu Basking Temperatures

Reptiles love to bask, and Tegus are no exception. They will frequently want a place where they can spread themselves out on a nice warm rock or platform and soak up some UVB and some heat. Tegus like the heat and need a basking spot that reaches temperatures 100-110 as juveniles and up to 115-130 degrees Fahrenheit when fully grown.

This can be done by giving the Tegu access to a raised platform closer to a heat lamp, where the temperatures are much higher. This also benefits them by allowing them to soak up some UVB to absorb the calcium from their supplements better and synthesize the vital vitamin D3.

You can also use a heating pad to set up a basking area where they can lay directly on the heat. Remember, it is essential always to use a proper thermometer to check these basking areas’ temperatures. When adjusting temperatures, one should never guess less you injure your reptile or start a fire. 

Tegu Humidity Levels

Tegu Humidity Levels

One of the biggest challenges for tegu owners is getting the right humidity levels in their enclosure. Tegus come from humid environments and need a good amount of humidity to stay healthy. But what are the ideal humidity levels for a tegu and how do you get the levels right in its enclosure? 

Tegus need anywhere from 75-90% humidity. It’s best to offer a few different levels of humidity in various spots in their enclosure. For example, you could create a humid hide with a high humidity level and make a basking area with lower humidity. 

Tegus, like every other reptile, have rather specific needs as far as their environment goes. However, unlike some dessert-dwelling lizards, tegus require a decent amount of humidity to stay healthy. Before you commit to owning a tegu, you must understand its humidity needs.

Tegus need humidity to survive. Before you commit to getting a tegu, you’ll want to learn how you can provide them with their particular humidity needs. You’ll also learn what you need to do to adjust your tegu’s humidity levels and different methods for ensuring your tegu is provided with enough humidity. 

Creating The Ideal Tegu Humidity Levels

The optimal humidity range for tegus is anywhere between 75-90%. While it is okay to lean toward one end of the spectrum or the other all over the tank, it’s preferable to have different humidity ranges throughout their enclosure. This allows your tegu to soak in the humidity and get away when needed. 

How to Perfect the Humidity Levels

With a tegu, you have many options for setting up sections in their enclosure, especially as they get older. Tegus are pretty large animals, growing to about 4 feet long. As is the case with most reptiles, your tegu will need a cage that is double their length. Ideally, you would use an 8 x 4 x 4-foot tank. A tank of that size means lots of space. 

Here are the steps for dividing your tegu’s tank into sections:

  • Choose a basking spot. The basking spot is the most crucial area of the entire tank. Usually, basking spots are placed in the middle of the tank. If you put it in the center of the tank, the basking spot can serve as your humidity “middle ground.” The basking spot should be around 80-85% humidity.
  • Choose a moist humid spot. Tegus love to have large water dishes, so choose a side for one to go on. Whatever side you choose will become the moist side. There, you can construct their humid hide; it doesn’t have to be much. You can use a large hollow log. To boost the humidity, you can add things like coco-fiber and moss. The humidity in the moist area should be around 90%.
  • Choose a dry spot. Your dry spot will be situated in the leftover space. You can do a lot in this area. You can add decoration or whatever you want, put their food bowl here, or add a little space for them to burrow. Though it is a dryer area, you might want to add a little bit of moss or coco-fiber to hold some humidity. This spot should be around 75% humidity.

Once you’ve prepared the tank, your tegu is ready to move in. Since it is divided, you should be fine letting the humidity self-regulate. However, always keep a hygrometer on hand to check the humidity a few times a day. You can also do this with an in-tank humidity monitor or a heat gun. 

Why Tegus Need Proper Humidity Levels

Since they are rainforest-dwelling animals in the wild, tegus thrive in high humidity. The most common type of tegu to keep in captivity is the Argentine tegu. These animals hail from the Brazil/Paraguay area in South America.

All wild Argentine tegus live in a humid, subtropical climate. So naturally, tegus need high levels of humidity. 

The Argentine black and white tegu is my top pick in the tegu family. To find out more about the Argentine tegu check out my Argentine black and white tegu guide! It covers just about everything you want to know before purchasing tegu. 

Tegus in captivity don’t just need humidity to emulate their natural environment, though. Humidity also helps tegus shed their skin easily since moisture helps prevent the old skin from clinging to the fresh skin. Humid hide boxes are the perfect way to give your tegu a high-humidity place to shed. 

Without the proper humidity, your tegu is susceptible to necrosis, which may cause its limbs and tail to lose circulation and die or fall off. Necrosis is a prevalent problem with low-humidity desert reptiles.

If you do notice stuck shed on your tegu, never peel it off. Instead, use some warm water and a soft toothbrush to loosen it so that it falls off. 

How To Keep Your Tegu Enclosure Humid

There are a few different ways you can boost the humidity in a tegu’s tank. What ever method you choose, make sure you’ve thoroughly researched the method and the impacts it may have on your tegu. You can boost tank humidity by using substrates and misting systems.

Choose A Humidity Boosting Substrate For Your Tegu

One of the most common ways to keep the overall tank humidity up is through substrates. There are a couple of different substrate options, and you can mix and match them to get the perfect one for you. 

Humidity-boosting substrates include:

  • Coco-fiber. Coco-fiber is made by shredding up the husks of coconuts. It is also sometimes mixed with a little bit of soil to give it a denser texture. With coco-fiber, you don’t risk impaction (constipation) because the fibers are digestible. This substrate can absorb tons of water, making it optimal for humidity.
  • Cypress mulch. Like coco-fiber, cypress much is usually mixed with potting soil. It is very dense, meaning it will hold a lot of water, and there is no risk of impaction. Also, it can absorb odors, which is something you’ll appreciate. If you can’t find cypress mulch, don’t be concerned; other tree materials like orchid bark are also acceptable. You can also mix in some reptile-safe soil into the cypress mulch as well. 

Whatever you do, resist the urge to use sand in your tank. Sand is not dense, so it doesn’t hold humidity. Sand is also known for causing impaction in reptiles, which can be harmful and sometimes fatal if it is not caught in time. 

Do Tegus Need Misting Systems Or Humidifers?

Another way to add humidity to the tank is to use reptile foggers or a misting system. There are a few different methods people use for misting. The one you choose will depend mostly on your budget and how much free time you have on your hands. 

There are machine misters and foggers available that sit directly in the tank and release mist on a timer. These systems are bound to save you lots of time, and they will fully automate the process to ensure that your humidity levels stay consistent. However, buying one of these will not excuse you from checking the humidity regularly; you will still need to do so. 

The other misting method is a little more time-consuming, though it is easier on the pocketbook. You can simply buy a spray bottle, set it to mist, and spray away. If you choose this method, you’ll need to mist the tank a couple of times a day. Since you’re in control here, you will need to be sure that you don’t completely drench the substrate. 

If you don’t think you’ll remember to do the misting every day, you can buy a little humidifier as a backup. A humidifier is not a replacement for misting, but it will help keep the humidity high enough to keep your tegu comfortable. 

You can buy an in-tank humidifier or leave one in your room, close to the tank. However, having a humidifier in the tank will raise the humidity higher than just leaving one in the room. 

Creating the Ideal Humidity Levels for Your Tegu

So what are the ideal humidity levels for tegus? Tegus need a humidity range between 75-90% to stay happy and healthy. If they’re cared for properly, a tegu can live up to 20 years in captivity. There are many ways to keep the humidity where it needs to be in the tank.

The best thing you can do as a tegu owner is to use your best judgment to decide what you need.  

Tegu Lighting

Lighting Requirements for Argentine Tegus

The Argentine Tegu and other tegus species require an all-day average UVI zone range between 2.6-1.0, requiring a gradient of 2.6 UVI on the basking end of the enclosure reducing down to zero on the opposite end. Tegus require a minimum of 12-14 hours of direct UVB exposure to maintain their health.

We understand that this may answer the question technically, but doesn’t help you in the slightest. For the rest of this article, we will be breaking it down into digestible chunks to help you know exactly what lighting to purchase.

Proper Lighting Setup for Your Tegu Enclosure

Argentine Tegus’ are considered open or partial sun baskers, meaning they bask in direct sunlight for a few hours each day and spend the rest of the day in little to no UVI in the shade. In your enclosure, you will want to create a gradient of 2.9-7.4 UVI as the basking spot on one side, reducing down to zero UVI on the opposite end. 

Lighting Options for Tegus

While lighting for your Tegu can get complicated, it doesn’t need to be. Here’s a basic outline of all the best lighting options.

Basking Bulbs

These incandescent bulbs are shaped specifically to direct an intense spotlight of UVB and heat in one area. Making it easy to obtain a high UVI with one or two bulbs. They range 50watts – 150watts, the higher the wattage the more heat you get.

Depending on how big the enclosure is, that will determine what bulb to buy. Your Argentine tegu will require a basking spot that reaches higher temperatures than the rest of the enclosure. 

Infrared Lighting

Infrared is invisible light, providing your Tegu a nighttime heat that doesn’t interrupt their natural sleep cycle.

Incandescent Heat Bulbs

Just like basking bulbs, incandescent heat bulbs give off a good amount of UVB and heat. Instead of creating a spotlight, they heat a larger area causing the UVI to decrease rather quickly the farther away from the bulb. Use these for the rest of the length of the enclosure to create that UVI gradient mentioned above.

Red and Black Incandescent Heat Bulbs

Red and black heat bulbs work great to create heat and small amounts of UVB. They are mostly used at night. Tegus are diurnal, meaning they are active during daylight hours and sleep at night. These allow you to still be able to provide some heat at night without the bright daylight light, keeping their natural sleep cycle consistent

High Output Fluorescent Heat Bulbs

Fluorescent bulbs don’t get as hot as incandescent bulbs, but do last about 15 times longer than incandescent, giving you a more energy-efficient bulb. To ensure that you are getting the most heat and UVB out of a fluorescent bulb, choose a high-output (HO) version.

Situating the fluorescent bulb next to a basking bulb will help achieve a gradual UVI. You might have to have a few to get the right amount of UVI.

Halide and Mercury Vapor Bulbs

When heating a large enclosure, you’d have to use quite a few incandescent and fluorescent bulbs to get the temp and UVI that is needed for Tegus. 

Halide and Mercury bulbs emit higher levels of UVB and heat a larger distance. These bulbs can help eliminate clutter while keeping the UVI and temperature perfect but do require a large amount of energy to run them.

LED Light Fixtures

On the topic of energy-efficiency, LEDs have come a long way over the past decade or so. Unfortunately, despite these advancements, no LED on the market today can truly emit enough UVB, or heat, to be used for a Tegu enclosure. Stay away from them!

Using Depth to Create UVI Gradient

When creating the UVI gradient for your Tegu, you aren’t solely relying on different light bulbs to emulate it. You will also want to use depth. Basking areas, for instance, should be set up within 6-8 inches from the basking bulb itself. 

Setting up two basking areas, each at different depths away from the basking bulb, will allow your Tegu to choose what basking spot suits their needs best at any given moment

After the basking spots, the enclosure should get deeper and further away from the heat bulbs. The further away results in a lesser, or zero, UVI. This is easy to obtain with a deep bed of substrate, piled nice and high under the basking bulbs, then sloping down low on the opposite side of the enclosure. 

You can also provide something for them to hide inside or under to ensure that they have a zero UVI area to hang out in if they desire.

What is UVB and Why Does my Tegu Need It?

Ultraviolet, or UV, is a wavelength of radiation that comes from the sun. It’s split up into three different wavelengths; UVA, UVB, and UVC. UVB is incredibly important when raising reptiles and, simply put, the UVI, or UV Index is used to measure UVB. The closer to the UVB source, in this case, it is a light bulb and not the sun, the higher the UVI. 

The further away you are, the lower the UVI you receive. The UVI can easily be measured with a Solarmeter 6.5, helping create the exact environment to suit your Tegus’ needs.

Why UVB Light is Important for Tegus

UVB, partnered with heat, is the key to complete healthy body function. It is absorbed through the skin and converted to vitamin D3. Vitamin D3 helps regulate hormones, calcium absorption, cell division, and immune system support

When reptiles are exposed to low levels of UVB, they become vitamin D3 deficient, resulting in a few health issues including Metabolic Bone Disease.

Metabolic Bone Disease and Tegus

This occurs when the body doesn’t have enough calcium to phosphorus ratio to perform normal body function and begins to pull calcium from the bones. This ends up leaving the bones brittle, which can lead to fractures and also fibrous tissue in the body. The calcium to phosphorus ratio should be 2:1. 

MBD can easily be prevented with proper lighting as well as a powdered supplement. 

Tegus Love Natural Sunlight

It’s good practice to allow your Tegu to get a few hours of direct natural sunlight regularly if possible. Unfiltered sunlight has the highest amount of UVB levels and should be part of their daily routine. Of course, this is only if the weather permits.

So if you can provide an outdoor enclosure when the temperature levels are right this can help keep your tegu healthy. Of course, for many of us this is not and option. Thankfully, you can still keep your tegu healthy with proper lighting, humidity, and temperature levels in their indoor enclosure as well! 

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