Gecko Light Needs: Heat and UVB by Species

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Gecko light needs are not one size fits all. The gecko infraorder Gekkota holds roughly 2,491 described species, and they split into very different daily rhythms. Leopard geckos and tokay geckos are active at night.

Day geckos bask in full sun. Crested geckos fall in between, active mostly at dawn and dusk. Getting the heat source, the UVB output, and the light cycle right for your species matters.

This guide covers heat sources, UVB, tank temperature setup, and warning signs that lighting is wrong. For a full overview of daily care, see our gecko care guide. For enclosure layout, see gecko housing.

Why gecko heating and lighting needs vary by species

Leopard geckos (Eublepharis macularius) and African fat tailed geckos (Hemitheconyx caudicinctus) belong to the family Eublepharidae, the “eyelid geckos.” They have movable eyelids. Unlike most other geckos, they also lack adhesive toe pads.

That fits a life spent on the ground, not in trees. Their light needs center on ground level heat and a shaded retreat, not bright overhead sun.

Crested geckos (Correlophus ciliatus) and gargoyle geckos (Rhacodactylus auriculatus) are arboreal and crepuscular. They need climbing space and a modest UVB source. They are not full sun baskers, but they still benefit from light UV exposure.

Tokay geckos (Gekko gecko) are nocturnal and arboreal too. They are native to tropical rainforest and cliffs from northeast India through the Indo Australian archipelago. That means they also need vertical climbing surfaces near their heat source.

Day geckos (Phelsuma spp.) are the outlier. They are strictly diurnal and bask openly. Their gecko light needs include a strong UVB tube and a real basking bulb, a setup closer to a bearded dragon‘s than to a leopard gecko’s.

Heat sources: mats, ceramic heaters, and halogen bulbs

A heat mat for gecko enclosures is the standard pick for ground dwelling nocturnal species. It sits under one end of the tank, outside the glass. It warms the substrate without giving off visible light, which suits an animal active after dark.

This fits how a leopard gecko naturally absorbs heat. In the wild it soaks up warmth from sun warmed rock and soil rather than basking under open sky.

An overhead heater suits arboreal geckos better. A ceramic heat emitter gives off long wave infrared and warms the air and surfaces below it. A deep heat projector is a different product that emits shorter infrared wavelengths, which penetrate tissue more like sunlight, and both run without visible light.

Crested, gargoyle, and tokay geckos all do well under either type. The heater radiates warmth down through the climbing space instead of warming just one patch of floor.

Because they produce no visible light, they can run around the clock without disturbing a gecko’s sleep cycle. For day geckos, a halogen basking bulb, such as the Zoo Med Repti Halogen Basking Spot Lamp, is usually the right heat lamp for gecko basking, since it delivers strong daytime heat and visible light together.

Whichever heat source you pick, build a gradient rather than one set temperature. One end should run warmer for digestion and activity. The other end should stay several degrees cooler.

This lets the gecko move to whichever zone it needs. A gecko that cannot escape excess heat will struggle to digest food. One that never reaches a warm enough spot will struggle to fight off illness.

Does a gecko need a heat lamp?

Whether a gecko needs a heat lamp depends on the species and the room. Nocturnal, ground dwelling geckos like leopard geckos usually do fine on an under tank heat mat alone. That holds as long as room temperature does not drop too low overnight.

Diurnal day geckos need an actual heat lamp. So do most arboreal geckos, since a mat under the glass cannot warm a tall, climbing focused enclosure evenly.

The RSPCA gives a concrete threshold for leopard geckos: overnight temperatures of 18 to 20°C (64 to 68°F) are fine, and supplementary heat is needed only if the room drops below 18°C. Its crested gecko sheet uses the same 18 to 20°C night floor. A ceramic heat emitter on a thermostat is the safest way to add that background warmth without light that would disrupt rest.

UVB lighting for geckos

UVB used to be seen as optional for strictly nocturnal geckos. That view has shifted. Even geckos that avoid direct sun still get filtered UV exposure in the wild.

The clearest framework is the Ferguson zone system, published in the Journal of Zoo and Aquarium Research. Zone 1 covers crepuscular and shade dwelling species, with a UV Index of 0 to 0.7 in the main activity area and a maximum of 0.6 to 1.4 at the brightest spot. Zone 3 covers open or partial sun baskers, with a UV Index of 1.0 to 2.6 and a maximum of 2.9 to 7.4.

Leopard geckos, crested geckos, tokay geckos, and the satanic leaf tailed gecko are all placed in Zone 1. Giant, Standing’s, and neon day geckos are placed in Zone 3. Henkel’s leaf tailed gecko sits between them, at Zone 1 to 2.

Metabolic bone disease from vitamin D deficiency remains one of the most common health problems in pet reptiles. It is also largely preventable with the right lighting.

The RSPCA translates Zone 1 into equipment for leopard geckos: a 2 to 5 percent UVB tube covering a third to a half of the enclosure length at the warm end. Position it so the basking end reaches a UV Index near 0.7. The shaded hide should stay close to zero.

That mirrors the light gradient the species would find in a burrow and rock crevice habitat. For crested geckos, the RSPCA specifies a medium output 5 to 7 percent UVB lamp mounted at the top of the enclosure so the gradient falls away with height. An exotics veterinary clinic likewise calls UVB strongly recommended for the species, not optional.

UVB output fades well before the visible light does. Gecko lights of this type need replacing roughly every six months, whether or not the bulb still glows.

Day geckos need meaningfully stronger UVB than any nocturnal or crepuscular gecko. As Zone 3 animals they should reach a UV Index of roughly 1.0 to 2.6 across their basking area, with a peak up to about 3 under the lamp. This is the clearest split in gecko light needs across the group.

A UVB level that suits a leopard gecko would likely under light a day gecko. A day gecko’s UVB would be excessive for a leopard gecko’s shaded, ground level lifestyle. Match the bulb to the species instead of reusing one setup across every tank in the house.

Setting up gecko tank temperature and the light cycle

Gecko tank temperature should always be a gradient, never one number. For a leopard gecko, the RSPCA gives a basking zone of 28 to 30°C (82 to 86°F) and a cool end of 24 to 26°C (75 to 79°F), while PetMD’s veterinary reviewed sheet allows a warm end up to 90°F. Check both zones with two separate digital thermometers, not the dial on the heat mat.

Crested geckos generally do best in a narrower band. An exotics veterinary clinic gives 72 to 80°F, and the RSPCA gives a warm end of 26 to 28°C (79 to 82°F) with a cool end of 20 to 24°C (68 to 75°F). They are more sensitive to sustained heat above the mid 80s than a desert leopard gecko is.

Tokay geckos run warmer than either. PetMD’s veterinary reviewed sheet gives a basking zone of 90 to 105°F, daytime air of 80 to 85°F, and a cool end and night floor no lower than 75°F, with humidity held at 60 to 80 percent by nightly misting. Day geckos have no published veterinary figure; keepers hold a basking surface near 90°F with an ambient in the low 80s.

Temperature and UVB targets by gecko type

Every heat mat, ceramic heater, or halogen bulb needs its own thermostat. A thermostat cuts power before the heat source overheats the enclosure. It is the single most important piece of safety equipment in any gecko setup.

Check actual temperatures daily for the first few weeks after any change. Thermostat dials and built in sensors are not always accurate.

Run gecko lights on a fixed schedule. The RSPCA specifies a 12 hour on and 12 hour off cycle for both leopard and crested geckos. A simple plug in timer keeps that cycle consistent even when you forget.

Nocturnal species should have any heat lamp switched off at night. Instead, rely on a non light emitting heat source, such as a ceramic heater or heat mat, to hold overnight temperatures.

Signs that gecko heating or lighting is wrong

Metabolic bone disease is the most common result of inadequate UVB or an incomplete calcium and vitamin D3 supply. It shows up as poor appetite and weakness. It also causes an inability to walk normally.

A swollen or distorted jaw or legs is a warning sign of an advanced case. So are spinal or leg fractures and cloacal prolapse. Any of these needs a reptile veterinarian promptly.

Correcting heat and light after diagnosis is only part of treatment. A vet will usually confirm the disease with blood tests and imaging. Calcium and vitamin D3 support typically follow.

Waiting rarely helps, since bone changes can become permanent. Low humidity combined with poor heating can also cause dysecdysis, or stuck shed. A gecko that cannot reach the right temperature and humidity zone struggles to complete a normal shed.

A stuck shed usually resolves with a warm soak in the mid 70s to mid 80s Fahrenheit for several hours. Follow it by gently working the retained skin free with damp gauze.

If a gecko is regularly refusing food or hiding in the coolest part of the tank, check its setup first. The same goes for a gecko that looks pale and sluggish. Incorrect gecko light needs are a common, fixable cause of these symptoms.

For product options, our guides to UVB lighting and thermostats cover specific bulb and controller types. Species pages go deeper still. See day gecko lighting for Phelsuma specific UVB and basking setups, and tokay gecko heating and lighting for that species’ needs.

Round out husbandry with our guides to gecko diet, gecko health, gecko breeding, and gecko behavior.

Frequently Asked Questions

Does a gecko need a heat lamp?

It depends on the species. Ground dwelling nocturnal geckos like leopard geckos usually do fine on a thermostat controlled heat mat. Arboreal or diurnal geckos such as crested and day geckos need an actual heat lamp or ceramic heater instead.

What temperature should a gecko tank be?

Most geckos need a gradient rather than a single number. The RSPCA gives a leopard gecko a basking zone of 82 to 86°F and a cool end of 75 to 79°F. A crested gecko does best around 72 to 82°F on the warm side with a cooler end in the low 70s.

Do all geckos need UVB lighting?

Current guidance recommends low level UVB even for nocturnal geckos. Leopard, crested, and tokay geckos are Ferguson Zone 1 animals, with a UV Index up to about 0.7 in the activity area. Day geckos are Zone 3 and need a UV Index of roughly 1.0 to 2.6, since they bask in direct sun in the wild.

Can I use a heat mat instead of a heat lamp for my gecko?

A heat mat for gecko tanks works well for ground dwelling nocturnal species like leopard geckos. Arboreal geckos generally need a heat lamp or ceramic heat emitter instead, since a mat under the glass warms climbing space unevenly.

How often should gecko UVB and heat bulbs be replaced?

UVB output fades well before a bulb stops producing visible light. Most UVB bulbs need replacing about every six months. Heat bulbs and ceramic heat emitters can be checked with a thermometer and swapped once output drops.

Is a thermostat really necessary for gecko heating?

Yes. A thermostat cuts power to a heat mat, ceramic heater, or basking bulb before it overheats the enclosure. It is the most important safety device in any gecko setup, regardless of species.