Enclosure: Lighting & UVB

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Boa constrictors do best with a 13:11 photoperiod, which means that they like 13 hours of light followed by 11 hours of darkness. During the winter months this can be switched to 11 hours of daylight and 13 hours of darkness. For best results, use a photoperiod of 12 hours light/12 hours dark during spring and summer for a more natural change between the seasons.

No light should be provided at night. Boas are nocturnal, and their eyes are evolved to see quite well in what humans perceive as total darkness. Providing a light source at night disrupts the snake’s day/night cycle and can negatively affect their health over time.


According to the UV Tool, Boa constrictor (and presumably other members of the Boa genus) is categorized under Ferguson Zone 2, which describes partial sun/occasional baskers, like most other snakes. Arcadia Reptile recommends a basking UVI of 2.0-3.0.

We recommend the Arcadia T8 Forest 6% or the Zoo Med T8 Reptisun 5.0, housed in a **reflective** T8 fixture, long enough to span half of the enclosure, and placed on the warm side.

The basking branch should be placed as follows. Recommended distance accounts for snake placement on top of the basking surface:

  • UVB mounted over mesh: basking branch 7-10” below UVB lamp
  • UVB mounted under mesh: basking area 11-16” below UVB lamp

(These recommendations are approximations based on available data. For best results, use a Solarmeter 6.5 to determine the best placement to achieve a UVI of 2.0-3.0 in the basking area.)

PRO TIP: Don’t forget to change your UVB bulb every 12 months!!

Boa Lighting Guide - Boa imperator basking under UVB lighting

Is UVB required?

Most sources will tell you that UVB is not required for a healthy boa, and while they are right in saying that a boa will not die within a year if it does not get UVB exposure, this belief is minimalist and outdated.

Recent studies are supplying mounting evidence that UVB is beneficial for snakes’ long-term physical and mental health, and it provides one of the keys to maximizing a boa’s lifespan. In the interest of encouraging a higher standard of reptile care, we at ReptiFiles believe that some degree of UVB exposure should be available to any reptile species in captivity.


Keep reading:

  1. Introduction to Boas
  2. Members of the Boa Genus
  3. Red-Tailed Boa Shopping List & Starter Kit
  4. How to Select and Buy a Pet Boa
  5. Enclosure Size
  6. Lighting & UVB Requirements ← YOU ARE HERE
  7. Temperature Requirements
  8. Humidity Requirements
  9. Substrate Options
  10. Enclosure Decor & Environmental Enrichment
  11. Feeding Your Boa
  12. Taming & Handling Tips
  13. Common Illnesses & Other Health Information
  14. Additional Resources