Bearded Dragon Temperature and UVB Chart by Age
A bearded dragon temperature and UVB chart by age: basking, cool side, and night temps for babies through adults, plus UVB bulb type and replacement timing.
Quick answer: Babies and juveniles need a basking spot of 100 to 110 degrees Fahrenheit; adults need 95 to 105. The cool side stays 75 to 85 at every age, and nights can safely drop to 65 to 75 with no heat needed above 65. Use a linear T5 HO 10.0 UVB bulb mounted about 12 inches from the basking spot and replace it every 6 to 12 months.
Heat and UVB are not optional extras for a bearded dragon, they are life support. Correct temperatures let your dragon digest food and stay active, and proper UVB lets it make vitamin D3 to absorb calcium. Get either one wrong and you risk illness, so use the chart below to dial in your setup by age.
Heating and UVB Essentials
Zoo Med Zoo Med T5 HO ReptiSun 10.0 UVB
$53.96 on Amazon
The standard high-output linear UVB tube for dragons.
Fluker's Reptile Basking Spot Bulb 100W
$5.59 on Amazon
Provides the focused heat for a proper basking zone.
Temperature chart by age
| Age | Basking spot | Cool side | Nighttime |
|---|---|---|---|
| Baby (0 to 3 months) | 100 to 110°F | 80 to 85°F | 65 to 75°F |
| Juvenile (3 to 12 months) | 95 to 105°F | 78 to 85°F | 65 to 75°F |
| Adult (12 months and up) | 95 to 105°F | 75 to 85°F | 65 to 75°F |
UVB reference
| Factor | Recommendation |
|---|---|
| Bulb type | Linear T5 HO 10.0 (desert reptile) |
| Bulb length | About two thirds to three quarters of the tank |
| Distance to basking spot | About 12 inches (follow the bulb's chart) |
| Mounting | Inside tank or over open mesh; glass blocks UVB |
| Daily photoperiod | 10 to 12 hours, off at night |
| Replacement | Every 6 to 12 months |
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Why these numbers matter
Bearded dragons are ectotherms, meaning they rely on external heat to power digestion and movement. The hot basking spot lets them raise their body temperature, while the cool side lets them shed excess heat, so the gradient across the tank is what keeps them comfortable and healthy. Babies run hotter because rapid growth demands faster digestion.
UVB does a different job: it lets the skin produce vitamin D3, which the body needs to absorb calcium from food. Without enough UVB, even a calcium-rich diet cannot prevent metabolic bone disease. Because UVB output fades invisibly, an old bulb is one of the most common hidden causes of illness, which is why the replacement schedule matters as much as the bulb choice. Pair correct lighting with the right tank size and supplement schedule for a complete setup.
Frequently Asked Questions
What temperature should a bearded dragon basking spot be?
Babies and juveniles need a hotter basking spot of about 100 to 110 degrees Fahrenheit, while adults do best at about 95 to 105 degrees. Measure the surface temperature right where the dragon sits, not the air, using a digital probe or infrared thermometer. A proper basking temperature lets your dragon reach the body heat it needs to digest food and stay active.
What UVB bulb do bearded dragons need?
Bearded dragons need a high-output linear T5 HO 10.0 UVB bulb that spans about two thirds to three quarters of the tank length. Coil and compact UVB bulbs are weaker and less even, so a linear tube is the standard. Mount it inside the tank or above an open mesh top, since glass and plastic block UVB. Position the dragon roughly 12 inches below the tube at the basking spot.
How often should I replace the UVB bulb?
Replace a UVB bulb every 6 to 12 months even if it still produces visible light, because the UVB output fades long before the bulb burns out. Quality T5 HO bulbs often last up to 12 months, while older fluorescent styles may need replacing every 6 months. Mark the install date on the bulb and use a UV meter if you want to confirm output. Aging bulbs are a common hidden cause of metabolic bone disease.
What should the cool side temperature be?
The cool side of the tank should stay around 75 to 85 degrees Fahrenheit at all ages. This temperature gradient, hot on one end and cool on the other, lets your dragon move back and forth to regulate its body temperature. Without a cool retreat, a dragon can overheat. Place the food dish and a hide on the cool side and the basking branch under the heat lamp.
Do bearded dragons need heat at night?
Most bearded dragons do not need any nighttime heat as long as the room stays above about 65 degrees Fahrenheit. A natural drop to between 65 and 75 degrees at night is healthy and mimics the desert. Turn off all white and basking lights at night for proper sleep. If your home gets colder than 65, use a ceramic heat emitter or a deep heat projector on a thermostat, never a colored night light.
Should I use a thermostat with the basking bulb?
A thermostat is strongly recommended for ceramic heat emitters and heat projectors, and helpful as a safety cap on basking bulbs in warm rooms. It prevents dangerous overheating if the room temperature climbs. Pair the thermostat probe with separate thermometers at the basking spot and cool side so you can verify the gradient directly. Reliable temperature control protects your dragon from both overheating and chilling.
How do I measure tank temperatures accurately?
Use a digital probe thermometer or an infrared temperature gun to read the actual surface where your dragon basks, plus a second thermometer on the cool side. Avoid the cheap round stick-on dial gauges, which are inaccurate and only read air temperature. Check temperatures at the start, since a new setup often needs the basking bulb wattage or height adjusted to hit the target range.
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