# Bearded dragon temperature checker

> Enter your measured basking, cool-side, and night temperatures and this checker returns an OK, CAUTION, or RISK verdict for each zone against the published bands. The bands follow Badham (1971) and the ReptiFiles bearded dragon temperatures guide by Dr. Jonathan Howard.

## Direct answer

A bearded dragon basks best with a surface temperature of 108–113 °F (42–45 °C), a cool side of 77–85 °F, and night temperatures of 55–75 °F. Measure the basking spot with an infrared thermometer, use a digital probe for the cool side, and re-check the night drop after lights out.

## Check your temperatures

Use the interactive calculator on the page: https://petguidecalc.com/reptile/bearded-dragon-temperature/ — enter measured basking, cool-side, and night temperatures plus the basking light source, and get an OK, CAUTION, or RISK verdict per zone with guidance.

## Bearded dragon temperature bands

| Zone | Target range °F | Target range °C |
|---|---|---|
| Basking surface | 108–113 °F | 42–45 °C |
| Cool side | 77–85 °F | 25–29 °C |
| Night | 55–75 °F | 12–24 °C |

Bands from Badham (1971) and the ReptiFiles bearded dragon temperatures guide. Measure the basking surface with an infrared thermometer; use digital probes for cool side and night.

## Basking UV index hierarchy

| Level | Value | Note |
|---|---|---|
| Ferguson Zone 3 target band | UVI 3.0–6.0 | The published target band for a bearded dragon basking spot. |
| Recommended landing subrange | UVI 4.0–4.5 | Dr. Howard (ReptiFiles) recommends landing here. It sits inside the 3.0–6.0 band and is not a replacement for it. |

The 4.0–4.5 landing range sits inside the 3.0–6.0 Ferguson Zone 3 band. Verify the real UV index at the basking surface with a Solarmeter 6.5.

## How the temperature check works

The bands come from two sources: Badham (1971), whose field study of the bearded dragon, Amphibolurus barbatus, documented the species’ thermoregulatory behavior, and the current ReptiFiles bearded dragon temperatures guide by Dr. Jonathan Howard, which sets 108–113 °F for the basking surface, 77–85 °F for the cool side, and 55–75 °F at night.

Each measured temperature is classified with a 4 °F margin. Readings inside the band return OK, readings within 4 °F of an edge return CAUTION, and anything further out returns RISK. The overall verdict is the worst of the three zones, so a single RISK reading drives the headline result even when the other two zones are fine.

Worked example: enter 110 °F, 80 °F, 65 °F (basking, cool side, night) with a halogen flood. All three zones return OK because each reading sits inside its published band (108–113 °F, 77–85 °F, 55–75 °F).

Humidity is checked separately against the 30–60% band, and the light source adds context: halogen floods are the recommended primary basking source, while a heat mat on its own cannot raise ambient air temperature. Basking light also needs the right UV index: Ferguson Zone 3 targets UVI 3.0–6.0, with 4.0–4.5 as the recommended landing subrange, not the whole band.

## Bearded dragon heating questions

**Q: What temperature should a bearded dragon basking spot be?**

ReptiFiles, in the bearded dragon temperatures guide by Dr. Jonathan Howard, sets the basking surface at 108–113 °F (42–45 °C), measured with an infrared thermometer at the spot your dragon actually sits. This checker returns OK inside the band, CAUTION within 4 °F of an edge, and RISK beyond that. The range also traces back to the field work of Badham (1971) on thermoregulatory behavior.

**Q: What is the right cool-side temperature for a bearded dragon?**

Keep the cool side between 77–85 °F (25–29 °C), per ReptiFiles, so your dragon can leave the basking spot and regulate. Readings below 73 °F or above 89 °F fall outside the 4 °F caution margin and come back RISK in this checker.

**Q: What temperature should a bearded dragon enclosure be at night?**

Night temperatures can drop to 55–75 °F (12–24 °C), per ReptiFiles, with no heat needed if your room stays in that band. Below 55 °F, add a ceramic heat emitter on a thermostat. This checker flags readings within 4 °F of the band edges as CAUTION and anything further out as RISK.

**Q: What UV index does a bearded dragon basking spot need?**

The Ferguson Zone 3 target band is UVI 3.0–6.0. Dr. Howard (ReptiFiles) recommends landing around 4.0–4.5 as a comfortable subrange, but that range sits inside the wider band rather than replacing it. Confirm the reading at the basking surface with a Solarmeter 6.5.

**Q: How do I measure bearded dragon temperatures accurately?**

Measure the basking surface with an infrared thermometer aimed at the spot your dragon occupies, and use digital probes for the cool side and night readings. Re-check weekly, because halogen output drifts with age. A thermostat holds the 108–113 °F basking target far more reliably than manual adjustment.

## More reptile tools

- [Reptile UVB Calculator](/reptile/uvb-calculator/) — Bulb distance and UV index by species, for the light half of the basking setup.
- [Reptile Heat Lamp Wattage Calculator](/reptile/heating-wattage-calculator/) — Halogen starting wattage by species, enclosure height, and room temperature.
- [All Reptile Care Tools](/reptile/) — The reptile hub, including humidity, calcium, incubation, and feeding tools.

## References

The temperature bands and the UV index hierarchy come from the sources below, accessed September 2026. Badham 1971 is cited textually as the historical basis for the basking range.

- [Effects of vitamin D3 supplementation and UVb exposure on the growth and plasma concentration of vitamin D3 metabolites in juvenile bearded dragons (Pogona vitticeps)](https://doi.org/10.1016/j.cbpb.2010.02.008) — Oonincx DG, Stevens Y, van den Borne JJ, van Leeuwen JP, Hendriks WH, Comp Biochem Physiol B Biochem Mol Biol, 2010.
- [Bearded Dragon Temperatures & UVB](https://reptifiles.com/bearded-dragon-care/bearded-dragon-temperatures-uvb/) — Dr. Jonathan Howard, Mariah Healey, ReptiFiles. Source for the 108–113 °F basking band, the 77–85 °F cool-side range, the 55–75 °F night range, and the UVI 4.0–4.5 landing suggestion inside Ferguson Zone 3.
- [Bearded Dragon Care Guide](https://reptifiles.com/bearded-dragon-care/) — ReptiFiles, reptifiles.com. General bearded dragon husbandry context for heating, humidity, and enclosure setup, including the 30–60% humidity target.
- Badham, J.A. 1971. Social and thermoregulatory behaviour of the bearded dragon, Amphibolurus barbatus. Copeia 1971(3): 484–497. — Field study of bearded dragon thermoregulatory behavior; the historical basis for the basking temperature target this checker uses.

_Educational resource, not veterinary advice. PetGuideCalc — https://petguidecalc.com_