Terrarium Climate Zone Reference
A general reference for the three broad terrarium climate categories. These are starting points only — always research your specific species' actual care requirements, since needs vary significantly even within a category.
What the three bands describe
The reference splits enclosures by the humidity they hold, because that decides nearly every other build choice:
- Arid, 10-40% RH - warm by day with a real night drop, dry substrate and generous ventilation.
- Tropical, 60-90%+ - warm and steady, misted or fogged on a schedule, over a substrate that holds moisture.
- Temperate, 40-60% - moderate on both counts, with wider seasonal and day-to-night swing than the tropical setup.
These are the conditions averaged over the enclosure. An enclosure should never hold one number everywhere: build a warm end and a cool end so the animal chooses, and let a misted tropical tank dry back between cycles rather than sitting at 90% around the clock.
Hitting and holding the numbers
- Measure where the animal lives. A digital probe at substrate level reads differently from a dial gauge stuck to the glass, often by 15 points of humidity.
- Ventilation and humidity pull against each other. Raise humidity by partially covering a screen top, deepening moisture-holding substrate, moving the water dish over the warm end or adding live plants - but never by sealing the enclosure. Still, wet, stagnant air grows mould.
- Heat from outside the glass, on a thermostat, and check the surface temperature of any basking spot rather than trusting the wattage.
- An arid enclosure is not a hot enclosure. Many desert species need a night temperature drop, and a heat source that runs all night removes it.
Frequently asked questions
What humidity should a tropical terrarium be?
Broadly 60-90%, allowed to fall between mistings rather than pinned at the top. Check your species' range first - a crested gecko and a dart frog sit at opposite ends of that band.
How do I raise humidity in a terrarium?
Cover part of the screen top, use a deeper moisture-retaining substrate, put the water dish at the warm end, add live plants, and mist or fog on a timer. Keep some airflow throughout.
What is a temperate terrarium?
The middle band: 40-60% humidity, moderate ventilation, and deliberate variation between day and night and across seasons rather than one constant setting.