When trying to keep a reptile healthy, one of the most vital pieces of equipment is a good thermometer.
Temperature and humidity play a big part in determining the happiness–and healthiness–of your reptile or amphibian.
On this page, we’ll discuss all the reasons you need to invest in a quality reptile thermometer, as well as describe the differences between certain models.
Why Monitoring Your Reptile Terrarium Is Important
Temperature is immensely important, no matter whether your terrarium houses a bearded dragon or a family of baby tortoises. Having the right temperature levels at all times ensures the health and wellness of your scaly friends.
Reptiles are ectothermic, which means that they need external sources to help regulate their body temperature, like the sun or a heat lamp. That’s why reptiles have become known as “cold-blooded” animals.
Each kind of reptile and amphibian has a thermal optimum, which is essentially the temperature they require to have peak body function. For monitor lizards, that internal temperature might be 120 degrees Fahrenheit, while rain-forest lizards love a wet, humid 80 degrees.
When the temperature in your terrarium isn’t within the thermal optimum of your pet, a few things can happen:
- Volatile temperatures can impact a reptile’s digestion
- Low temperatures cause lethargy and laziness
- Sub-optimal temperatures can compromise a reptile’s immune system
The best way to avoid these problems is to invest in a good reptile thermometer and read up on optimal temperatures for your terrarium.
Types of Reptile Tank Thermometers
There are two main types of reptile thermometers: contact and infrared.
Contact thermometers usually have a long probe that sits inside the tank to record the temperatures, while infrared thermometers take a reading only when you point it in the tank.
In general, contact thermometers are the most accurate reptile thermometers you can find, but infrared are super easy to use. There’s trade-offs for each type of thermometer, so you just have to decide what’s important for you and your pet.
Here is some more information about the types of tank thermometers you’ll find for sale at pet stores and reptile suppliers.
Heating Cable Thermometers
These can be wrapped around most heaters with ease, and have a sensor at one end that is inserted into the substrate. The great thing about these is that they are usually waterproof, and can be used to measure the temperature at several different locations around the tank!
These are available in a few wattages but have an adhesive backing that can be stuck to any surface. These are very accurate within 2-5 degrees of the actual temperature, and some even have a probe on them as well!
These are not only used to monitor the temperature in your tank but will also turn on and off your heating devices as needed. These tend to be very accurate within one degree of the actual temperature. They often come with a probe that is inserted into the substrate, but some have more than one. We recommend these for more advanced keepers who want to accurately monitor their temperature.
Infrared Temperature Guns
These are also accurate within 1-2 degrees of the actual temperature and can be used to check the surface temperature of your animals at a distance.
IR thermometers are great because they don’t require surface contact, but they can be pricey and you need to buy one specifically made for reptiles. These kinds of thermometers are very convenient but there are a few variables that can impact their readings. Temperature fluctuations in the air around you might skew the reading, and if you’re measuring surface temperature, it might read hotter than air temperature.
What Makes a Good Reptile Thermometer?
Purchasing a reptile thermometer might seem like a pretty easy task, but there are a few factors you have to consider before jumping for a product. A lot of these factors are pretty easy to figure out simply by reading the product description and facts on the box. But, we figured we’d elaborate just to make crystal clear what makes for a good reptile thermometer
Reptile thermometers have to put up with a lot. Depending on what kind of enclosure you have, your thermometer might have to deal with high temperatures and high moisture levels on a regular basis. You want a thermometer that won’t malfunction in the face of prolonged heat and humidity.
Plus, you want a thermometer that won’t harm your pet reptile if they choose to play with it. They’re curious creatures, and sometimes they’ll poke around your in-tank probe thermometer, so make sure the material is non-toxic for pets. If you buy a thermometer specifically designed for terrariums, this shouldn’t be a problem.
More than anything else, you want your reptile tank thermometer to be accurate within a one or two degrees. Having a thermometer that runs hot or cold can impact the livelihood of your pet lizard, frog, or turtle, simply because their environment isn’t adjusted for their liking
Having an inaccurate thermometer is the equivalent of having a fire extinguisher that may or may not put out a fire. Albeit a dramatic comparison, the relationship between temperature and reptile happiness is too distinct to ignore.
When possible, purchase a high-quality probe thermometer. While infrared thermometers are more convenient, probe thermometers tend to be more accurate because they’re not impacted by radiant heat.
This trait is pretty easy to come by, since most thermometers are produced for international sale. You want a reptile tank thermometer that has both Farenheit and Celsius readouts.
A lot of reptile forums and websites online rely on Celsius temperatures, so having a dynamic thermometer makes it easier for you to know what’s what. Of course, you can always make the conversion with an online tool or in your head, but having both F and C readouts is nice to have.
Reptile Thermometer and Hygrometers
In order for reptiles to survive, not only does the temperature need to be within their thermal optimums, the humidity has to be within their humidity optimum.
Humidity is the amount of water vapor in the air, and it fluctuates widely depending on the time of year and where you live. Some reptiles require low humidity, such as those native to desert regions, while some frogs and rain-forest reptiles need high humidity. If your pet’s habitat isn’t humid enough, symptoms include:
- Difficulty shedding their skin (molting)
- Their eyes might appear sunken in
- Lethargy and weakness
What’s a Hygrometer?
A hygrometer is a very important piece of equipment for a terrarium. It measures the humidity level in your tank. Often, reptile thermometers and humidity gauges will be sold together, as one compact device.
If you’re just starting out with your terrarium or this is your first time having a reptile/amphibian as a pet, we suggest going for a reptile thermometer and humidity gauge all-in-one. They’re easier to use, and you can always upgrade in the future.
If you have an extensive terrarium already, it might be better if you buy an individual thermometer and hygrometer. That way, you can get more detailed readings of your terrarium environment, and can even use them for more than one terrarium.
How To Read A Reptile Thermometer
While some fish tank thermometers are color-coded, reptile thermometers are almost all digital, making them super simple to read.
A digital reptile thermometer should sit about halfway down the terrarium wall. You can use a command hook or some tape to affix it to the glass. The reason you want the reptile thermometer so low is that the middle of the tank will give you the most accurate temperature reading.
Too high and the temp reads not high enough, and too low, close to the lamp or heat rock, it reads too high.
Most good digital thermometers will have a function to change the temp from Fahrenheit to Celsius, so it’s just a matter of picking your preference and recording the read-out.
Reptile Thermometer FAQs
The thermometer/hygrometer combos are great for small enclosures, but if you’re dealing with a large chameleon tank or a bearded dragon terrarium, you’ll probably want two separate devices. You’ll want to place the thermometer in a different area of the tank than the hygrometer, and when they’re combined, you can’t do that.
Most thermometers for reptiles nowadays are digital, making them very easy to read. Simply look at the number displayed on the thermometer and check whether or not it’s within a healthy range for your pet.
Your thermometer should always be relatively central in your tank to ensure you’re getting the best reading. Try for an area that is directly under your heat source and close to any basking rocks you may have in the enclosure.