Complete Guide to Humidity Levels
Providing the best humidity levels for a bearded dragon in their microenvironment will support their health and well-being.
- 1. The best humidity level for bearded dragons
- 2. Understanding relative humidity
- 3. How to measure humidity
- 4. Controlling Humidity Levels
- 5. Health Issues Caused by incorrect Humidity Levels
- 6. How much Humidity do Bearded Dragons Get in the Wild?
- 7. Further Reading and References
1. The best humidity level for bearded dragons
What humidity do bearded dragons need? The great news is that bearded dragons don’t actually need a lot of humidity. The School of Veterinary Science UQ VETS Small Animal Hospital (part of the University of Queensland, Australia) recommend the ideal humidity bearded dragons need is between 30-40%. Where this guide references the ideal humidity, it is referring to 30-40%[3,11].
The recommended humidity level is very broad. It is covering all Pogona species, in all seasons, at any time of the day day or night and any season (summer or winter). In addition, it is referring to relative humidity.
To see what sort of humidity levels the bearded dragon experiences in its natural environment go to the end of this article – humidity levels for Pogona (vitticeps, barbata, minor, etc).
For bearded dragon keepers who live in Australia, only bearded dragons that naturally live in the state can be kept as pets. So chances are that if the housing you have provided is appropriate, then you will not have to adjust for humidity. However, monitoring is not only still prudent to ensure conditions remain suitable but in some cases, is a requirement of keeping. For example, in Queensland the Code of Practice for Captive Reptile and Amphibian Husbandry requires that keepers monitor the humidity in the enclosure regularly .
2. Understanding relative humidity
Relative humidity is the measure of how much water vapor the air is holding and it is expressed as a percentage. This is measured by percentage with the maximum level being saturation point, which is 100%. The hotter the air, the more water vapor it can hold. So the amount of water vapor in the air is relative to the temperature.
A relative humidity of 40% (ideal humidity level for a bearded dragon) means the air holds 40% of the maximum water vapor that it can at that temperature before it would become saturated.
“Air with a temperature of 30°C can hold more than three times as much water vapour as air at 10°C.” Commonwealth of Australia, Bureau of Meteorology.
This helps make it clearer to understand why night time humidity for bearded dragon housing sometimes seems to high. The humidity of the housing may seem fine during the day, but at night it appears to increase. In fact it is more likely that the temperature dropped, as it should do. When the temperature is lower the air cannot hold as much moisture as it did when it was hotter. This in turn increases the humidity level. Turn the heat back up and the relative humidity reading will start to decrease.
The warmer the air is, the higher its capacity to hold moisture. As temperature increases, the relative humidity decreases even though the water level remains the same. This relationship is important to understand in order to manage humidity.
3. How to measure humidity
To know how much humidity your bearded dragon tank has, install a hygrometer. A hygrometer measures the amount of humidity and water vapour in the atmosphere. For more on that subject see the Wikipedia Hygrometer page.
Hygrometers can be analogue or digital and either are suitable for your bearded dragon house.
Installing two hygrometers is best and that can be a combination of analogue and digital or two of the same type. Two hygrometers will provide a means to double check the reading. Some hygrometers are not reliable, particularly on the cheap range.
3.1. Types of Hygrometers
Analogue hygrometers have an advantage of not needing a battery like the digital hygrometers. On the other hand, they don’t have probes which provide a little more flexibility in placement. Installing both a digital and analogue hygrometer is useful and cheap.
3.2. Placement of Hygrometers
Hygrometers are best placed somewhat centrally. Unlike thermometers, there is a lot more flexibility in where they can be placed while still being effective however, there are some key things to understand.
In the section Understanding Relative Humidity above, we know that relative humidity is relative to the temperature. The temperature gradient you are providing in your bearded dragons housing has a range of around 20°C difference from one end to the other. Given that, where you place the hygrometer, cool end of the tank to the hot end, can make a huge difference to the humidity reading.
Assuming the housing heating and lighting has been set up correctly, just place the hygrometer or its probe centrally on the back wall.
Digital hygrometers may come with or without a probe. Hygrometers with a probe provide much more freedom of placement. The probe and digital display can be placed apart making it easy to put the display wherever you can access it best.
Don’t place the hygrometers or their probes in live plant foliage (artificial plant foliage is fine). Avoid corners where air circulation might be limited or over a water dish. These areas will exaggerate the level of water vapor in the air giving a reading that is not accurately reflect the environment.
Avoid letting the probe dangle down in the housing. A curious bearded dragon could always eat it. Place probes against a wall or accessory.
4. Controlling Humidity Levels
We know that humidity is all about the level of water vapor in the air. So it makes sense that to control humidity, you need to be able to adjust the amount of water vapor in the air.
Water vapor is added to the air through evaporation and transpiration and removed by condensation or freezing. If the humidity levels are wrong, then look at where evaporation or transpiration is occuring.
Before delving into adjusting the bearded dragons habitat, check the room the bearded dragon is housed in. It might be that your climate is humid, in which case that is where the focus needs to be. If it isn’t the wider environment, then investigate the animals housing.
Ensure you do one thing at a time to resolve humidity level issues and monitor the hygrometer over the next few hours to check the results. This way if anything corrects the issue, you will be able to pinpoint what the solution was.
4.1. How Do I make my reptile tank less humid?
To make your bearded dragon tank less humid, simply reduce the water in the environment, reducing evaporation and transpiration. Here are some quick and simple ways to lower the humidity for your bearded dragon:
- Check the placement of your hygrometer. The location of the hygrometer makes a difference to the reading. The cool side of the housing will give a different reading to the hot.
- Increase the ventilation. This is by far the easiest and quickest way to lower the humidity. Increasing ventilation in glass tanks is one of the reasons housing bearded dragons in glass tanks is problematic as it is difficult to add ventilation to a glass wall.
- Put a hygrometer near the tank in the room it is placed in to check if the environment is causing the issue. If it is, can the ventilation in the room be increased or the tank be moved to a different room that has less humidity?
- Reduce evaporation by moving any water sources away from heat. For example, move the water bowl to the cool end of the tank.
- Reduce transpiration by moving any live plants to another room.
- Place one or more socks of rice in the enclosure.
- If the humidity is at extreme levels it is presumably exasperated by climate, use a dehumidifier in the room.
A note on fans. Fans move air, so if there is a cool pocket and a warm pocket of air then it will circulate those together combining to a more even temperature. Fans may help reduce humidity if the humidity is due to trapped moisture (such as in tanks). Circulating and combining less moisture saturated air with a fan may help to reduce the humidity.
High humidity levels present far more danger than low humidity. Some keepers report humidity level increasing at night and not so much through the day. Reading the section in this article “What is relative humidity” will help explain why this may be the case as temperatures will drop during the night.
4.1.1. Adding ventilation
If the housing is made of melamine or other materials easily modified, then you can simply add more ventilation. What this will do is allow more air to circulate which will level out the humidity closer to that of the room the habitat is kept in. You can buy a vent from any hardware store in many different sizes.
Getting one that can be closed will be useful on days when you need to keep the heat in a bit more (such as winter).
Glass tanks are not good for bearded dragons. It is very difficult to add air circulation which is the easiest way to lower high humidity levels. Glass tanks have the perfect qualities for fish but not so good for creatures that need good air circulation.
Manufacturers and pet shops love to sell tanks because they are easy to mass produce and so they can make the prices very attractive. This reduces the cost of entry for new reptile keepers, however it is unlikely to be the best option for the health of the bearded dragon or the wallet of the pet owner as health issues may escalate.
If you have purchased a glass tank (aka reptarium, vivarium) then repurposed it for breeding and/or maintaining your own insects or perhaps as a quarantine environment.
If you love creating things yourself, then check the section on DIY housing. Even if you are not much with the old carpentry tools, there are some ways you may be able to get around it and make the housing practical, beautiful and something you can be proud of.
If lowering the humidity down to the ideal humidity level has not been successful with the quick and easy options above, then a dehumidifier may help. The desiccant and refrigerant dehumidifiers are reasonable options.
The desiccant dehumidifiers range from small portable units which can easily be added to any environment, to large ones suitable for rooms.
The Eva Dry Dehumidifier is one of the dehumidifiers which can be added directly to the environment.
It works using a renewable silica gel that absorbs moisture. Somewhere between 3-8 weeks the gel goes to its full capacity point and needs to dry out so it can remain effective.
Anything that is added into the enclosure must also become part of the cleaning routine. Consider how you will disinfect the dehumidifier when cleaning.
From there you can go into refrigerant dehumidifiers. The Comforday Compact Dehumidifier and is about the cheapest you are going to get at under $50 US.
The reservoir is very small, but it is cheap and shouldn’t really be doing that much work. If it is working too hard then the environment is really unlikely to be suitable to keep a bearded dragon.
4.2. How to Raise the humidity in your bearded dragon tank
To raise humidity in your bearded dragon tank simply add more moisture to the environment, increasing evaporation and transpiration. Here are some quick and easy ways to increase the humidity for your bearded dragon:
- Check the placement of your hygrometer. The location of the hygrometer makes a difference to the reading.
- Add a water dish towards, or in, the hot end of the tank (be mindful of hygiene, replacing water daily and water levels to prevent drowning).
- Mist branches, or soak them, and place them near the heat lamp (be wary of placement and possible hazards such as fire). This will only last for hours.
- Add plants, especially broad leaf plants. These will help bring moisture into the environment (ensure the plants are suitable for the bearded dragon).
- Add a fogger with a timer to come on at set intervals during the day.
Keep in mind that the room the enclosure is in is likely to directly affect the microenvironment. It might be that adjusting the room will resolve issues in humidity in the enclosure. Measure both the room and enclosure with a hygrometer to identify which one needs adjusting to resolve any humidity issues quickly.
Low humidity levels are relatively easy to increase. Simply misting the bearded dragons in their enclosure daily and ensuring they are hydrated (fluids by mouth) may be sufficient to compensate for low humidity. If you need help to get your bearded dragon to drink, see the article on teaching your bearded dragon to drink for more ideas.
5. Health Issues Caused by incorrect Humidity Levels
5.1. Is Too much humidity is bad for bearded dragons?
Too much humidity is bad for bearded dragons. High humidity presents danger of harmful bacteria and fungus thriving and reaching levels that exceed the resistance of the immune system. Exacerbated by small environments with waste such as faeces, uneaten food or other waste material the concentration levels of excessive pathogens can rise quickly. Health issues can include:
- Bacterial infections 
- Ulcerative or Necrotic Dermatitis 
- Mycotic disease 
- Respiratory diseases 
5.2. Is Low humidity bad for bearded dragons?
Low humidity is bad for bearded dragons, although easier to remedy through alternative means. The greatest immediate health concern for low humidity for bearded dragons is dehydration.
Serious dehydration is not the only threat. Constant mild dehydration can cause deadly health issues. Health problems which may be contributed to by low humidity are also ones that are attributable to dehydration and include:
- Avascular necrosis (juvenile Bearded Dragons are more susceptible)
- Dysecdysis (difficulty in shedding)[1, 3]
- Renal disease [2, 5]
- Non-obstructive Dystocia (eggs cannot be passed)
- Urinary tract disease 
6. How much Humidity do Bearded Dragons Get in the Wild?
The humidity bearded dragons get in the wild ranges from environment and season. However, bearded dragons such as the Pogona vitticeps (most commonly kept in captivity) generally range in areas of an average relative humidity between 30 and 50%.
The range of natural environments bearded dragons can live in is huge. The geographical distribution of each of the Pogona species varies. Along with that variation of territory, comes a range of different climatic conditions.
The map below shows the distribution of the Pogona vitticeps, Pogona barbata, Pogona henrylawsoni, Pogona minor and Pogona nullarbor. The distribution data is from the Australian Reptile Online Database (AROD) overlaid on a map from the Australian Government Bureau of Meteorology displaying the relative humidity ranges at 9am over a 30 year period (1961-1990).
On the map you can see quite a range in humidity levels for bearded dragons. This is great for a general idea but of course in reality, relative humidity goes up and down with temperature. So from one hour to the next, one season to another, the humidity fluctuates.
In the map below, the annual average at 9am and at 3pm are shown without the bearded dragon distribution overlay. This shows the humidity from one time in the day to another can range quite significantly. In the mornings, the relative humidity is higher than in the afternoons.
The following map shows the average annual humidity over a 30 year period for Summer in the month of January and a winter month of July at 9am. For the Pogona vitticeps (see distribution on the map at beginning of this section), 20-50% would cover most of their range.
7. Further Reading and References
- Bearded Dragons – Problems by Rick Axelson, DVM. Care & Wellness, Medical Conditions, Nutrition, Zoonosis and Human Health
- Acute and Chronic Renal Disease: Diagnosis, Treatment, and Prognosis in Lizards by Drs. Foster & Smith Educational Staff adapted from the information presented at the Western Veterinary Conference, 2003
- The School of Veterinary Science UQ VETS Small Animal Hospital (part of the University of Queensland, Australian)
- Preovulatory stasis and dystocia in oviparous lizards. Raffaele Melidone, Dr. med. vet.; Joyce S. Knoll, VMD, PhD, DACVP; and Nicola Parry, BSc, MSc, BVSc, DACVP. Veterinary Medicine. November 2008, 595-598
- Reptile and Amphibian Urinary Tract Medicine: Diagnosis and Therapy. Paul M. Gibbons, DVM, MS, Dipl ABVP (Avian Practice), Animal Emergency Center, Glendale, WI 53066 USA
- Hôpital Vétérinaire Chambly
- Mycotic Diseases of Reptiles by Stephen J. Divers, BVetMed, DZooMed, DACZM, DECZM (herpetology), FRCVS, Professor of Zoological Medicine, Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia
- Respiratory Conditions in Reptiles by Sean McCormack BSc (Hons), MVB, MRCVS. 30 December 2015
- Captive reptile and amphibian husbandry. Code of Practice. Wildlife management. Nature Conservation Act 1992. Department of Environment and Heritage Protection
- Atlas of Living Australia. https://www.ala.org.au/
- Handling and Nursing Reptiles. Proceedings of the Australian Veterinary Association New South Wales Division Conference, 16-18 September 2011, Tamworth
Distribution data Australian Reptile Online Database
Australian Government Bureau of Meteorology
What is humidity? How is it measured? Math and Science Activity Center