What humidity and temperature does a veiled chameleon need?

Temperature targets

Veiled chameleons (Chamaeleo calyptratus) come from the mountainous wadis of Yemen and south-west Saudi Arabia — climates with sharp day-night temperature swings and seasonal humidity. Captive husbandry mirrors that with a clear thermal gradient and a real night drop. Per Hopp'in Help's care sheet and PetMD's veiled chameleon care sheet:

Heating sources

A halogen flood bulb on a dimming thermostat above the screen top is the modern standard:

• Halogen flood sized for the basking distance — typically 50–75 W for a 24×24×48 in enclosure. The basking branch is positioned 25–30 cm below the top, where the chameleon can climb for direct exposure.
• Dimming or pulse-proportional thermostat with the probe at the basking branch surface (not in the air). Set to the male or female target.
• Cross-check with an IR temperature gun weekly on the actual basking branch.

No heat mats — chameleons don't thermoregulate from below. No bright overnight bulbs — they disrupt circadian rhythm and stress the chameleon. Detail in the cross-species UVB guide.

Humidity targets and the wet-then-dry cycle

This is where veiled chameleon husbandry differs from most other reptiles: humidity should not be constant. Per Chameleon Academy's hydration explainer:

• During and shortly after misting: 50–70 % humidity.
• Between misting cycles: humidity drops to 30–40 % as the enclosure dries.
• Never sustained above 70 % without ventilation — drives respiratory infection.
• Never sustained below 30 % — drives dehydration, the #1 captive cause of veiled chameleon death.

The wet-then-dry pattern mimics natural mountain conditions and prevents both extremes. To achieve it:

• 2–4 misting cycles per day, 1–2 minutes each. Programmable misters (MistKing) remove the daily-burden risk.
• First mist shortly after lights-on; encourages morning drinking from droplets on leaves.
• Last mist at least 1 hour before lights-off so the enclosure has time to dry overnight.
• No standing water on the floor or screen overnight.

For the full hydration setup including dripper logistics, see the hydration guide.

Why screen enclosures only

Glass tanks (Exo Terra style with sealed glass on all sides) are the wrong housing for veiled chameleons:

• Stagnant air — no cross-ventilation allows the wet-then-dry cycle to work. Humidity stays high all day.
• Respiratory infection driver — the documented combination (high humidity + no ventilation + warm temperatures) is the setup that drives bacterial RI.
• Limited evaporative cooling for the chameleon during hot basking periods.

Screen enclosures (Reptibreeze, DIY mesh, ZooMed ReptiBreeze) on all sides provide:

• Cross-ventilation between misting cycles, supporting the wet-then-dry humidity pattern.
• Heat layering — the basking spot warms, the cool side stays ventilated.
• Drainage when paired with a sloped tray base.

Standard size: minimum 24 × 24 × 48 in (60 × 60 × 120 cm) for an adult, 36 × 24 × 72 in (90 × 60 × 180 cm) preferred. See the pillar care guide.

Night temperatures

Veiled chameleons need a real night with a temperature drop, just as their native Yemen environment provides:

• Target 18–22 °C (65–72 °F) night-time across the whole enclosure.
• All heat and lights off — no red, blue, or white bulbs at night.
• Only add a low-wattage ceramic heat emitter if the room itself drops below 15 °C (60 °F) for sustained periods. Set on its own thermostat to switch in only at the floor temperature.

Skipping the night drop — running heat all night, leaving bulbs on — stresses the chameleon and disrupts hormone cycles.

How to measure correctly

Three tools, used together:

• Infrared (IR) temperature gun — point at the actual basking branch surface; that's the meaningful reading. Stick-on dials read air and lie about basking.
• Digital thermometer + hygrometer at mid-height for ambient air and humidity. Mount on the screen wall, not stuck to the glass.
• Cross-check monthly and after any equipment change.

Per the Merck Veterinary Manual, inadequate husbandry in chameleon care is a documented contributor to chronic illness — and the most preventable one with proper monitoring tools.

What goes wrong

Two patterns drive most preventable veiled chameleon illness:

1. Constant high humidity + sealed glass = respiratory infection. The chameleon presents with gaping mouth, mucus, audible breathing, lethargy. Fix the enclosure (switch to screen, fix the mist schedule), see a reptile vet within days.

2. Constant low humidity / missed misting = dehydration. The chameleon presents with sunken eyes, sustained dark coloration, orange urates, lethargy. See the dehydration signs guide — the #1 captive cause of death.

Both are preventable with the correct enclosure (screen), correct misting schedule (2–4 cycles with drying between), and weekly verification of temperature and humidity readings. The broader husbandry baseline is in the pillar care guide.