When the Temperature Drops, the Stakes Rise
Last January, we had an unexpected power outage that lasted about nine hours. It was 15°F outside, and by hour three, the temperature in my reptile room had dropped to 62°F and was falling fast. I was wrapping heat packs in towels, moving enclosures closer together, and seriously considering putting my ball python inside my jacket. That experience taught me two things: winter preparedness for reptile owners is not optional, and you don't truly appreciate your thermostat until it has no electricity to work with.
Cold weather presents unique challenges for reptile keepers. These are ectothermic animals — they depend entirely on external heat sources to regulate their body temperature. When your house gets cold, they get cold. And cold reptiles stop eating, become immunosuppressed, and can develop serious health problems or worse. Let's talk about how to keep that from happening.
Maintaining Enclosure Temperatures
The first and most important winter task is making sure your heating setup can actually handle cold weather. That heat lamp that keeps the basking spot at a perfect 100°F in July might struggle when the ambient room temperature drops 15 degrees in December.
Audit Your Heating Equipment
Before winter hits, do a thorough check of all your heating equipment:
- Check thermostat function: Make sure your thermostats are reading accurately by comparing them to a separate digital thermometer. Replace any that are reading incorrectly.
- Inspect heat mats and tape: Look for any discoloration, peeling, or damage. Heat mats degrade over time and can fail without warning.
- Test backup bulbs: Have spare basking bulbs on hand. Bulbs love to burn out on Saturday nights when the pet store is closed.
- Consider ceramic heat emitters: These provide heat without light, making them great for supplemental nighttime heating when temperatures drop after dark.
Room Temperature Strategies
The easiest way to stabilize enclosure temperatures is to stabilize the room temperature. A small space heater in your reptile room (with appropriate safety precautions) can make a dramatic difference. I keep my reptile room at 72°F year-round using a combination of the home's central heating and a small oil-filled radiator as backup. The oil-filled type is safer around animals than fan heaters — no exposed elements, no blowing air, and they maintain a consistent temperature.
Insulation helps too. If your reptile's enclosure is near a window or exterior wall, consider moving it to an interior wall for the winter. Cold drafts from windows can create invisible temperature drops that your thermostat might not catch if the probe is on the other side of the enclosure.
Nighttime Temperature Drops
Many reptiles naturally experience cooler temperatures at night, and a moderate drop (to around 65-72°F for most tropical species) is actually fine and can even be beneficial. The issue is when nighttime temperatures drop below the species' safe minimum. For most tropical reptiles, you don't want it going below 65°F. For desert species accustomed to cool nights, some can tolerate the low 60s, but check the specific requirements for your species.
Ceramic heat emitters connected to a thermostat are my go-to solution for nighttime heating. They provide warmth without disrupting the light cycle, and a good thermostat will kick them on only when needed.
Understanding Brumation
Here's where things get interesting. Some reptile species — particularly those from temperate regions — naturally enter a period of dormancy during winter called brumation. It's similar to mammalian hibernation but not quite the same. Brumation involves reduced activity, little to no eating, and extended periods of hiding, but the animal may still drink water and move around occasionally.
Species That Brumate
Common pet species that may attempt to brumate include bearded dragons, corn snakes, king snakes, box turtles, and many North American and European species. Tropical species like ball pythons, crested geckos, and chameleons generally do not brumate.
Should You Allow Brumation?
This depends on several factors. If you're breeding your reptiles, brumation is often a necessary trigger for reproductive cycling. If you're just keeping a pet, it's a personal decision with valid arguments on both sides.
Arguments for allowing it: it's a natural behavior, it may reduce long-term stress, and some keepers believe it contributes to longevity. Arguments against: it carries some risk (especially for animals that aren't in peak health), requires careful monitoring, and means you don't get to interact with your pet for weeks or months.
If you choose to allow brumation, the animal should be in excellent health with no parasites, should have had its last meal fully digested (typically 2 weeks after the last feeding), and should have access to fresh water throughout the process. Temperature should be gradually lowered to the species-appropriate range over a week or two, not dropped suddenly.
My bearded dragon has brumated the last two winters. The first time it happened, I was convinced he was dying. He stopped eating, barely moved, and spent all day in his cool hide. After some panicked research and a reassuring call to my vet, I learned to recognize the signs. Now I just make sure he's cleared out digestively, keep his water fresh, and let him do his thing. He usually comes back to full activity after 6-8 weeks, grumpy and hungry.
Humidity Challenges in Winter
Central heating is the enemy of humidity. During winter, indoor air can drop to 15-20% relative humidity, which is lower than most deserts. For species that need higher humidity — ball pythons, tropical geckos, most amphibians — this creates a real problem.
Strategies for Maintaining Humidity
- Increase misting frequency: What worked in summer may need to be doubled in winter.
- Use a room humidifier: Running a cool-mist humidifier in the reptile room raises the baseline humidity, making enclosure-level management much easier.
- Partially cover screen tops: Screen tops are humidity killers. Covering 50-75% of a screen top with aluminum foil, plastic wrap, or a custom acrylic panel makes a huge difference. Leave some ventilation — you're reducing airflow, not eliminating it.
- Switch to moisture-retaining substrates: Coconut fiber, cypress mulch, and sphagnum moss all hold moisture better than dry substrates. For species that need it, a deeper substrate layer during winter provides a humidity buffer.
- Larger water dishes: A bigger water dish means more surface area for evaporation, which passively raises enclosure humidity.
I struggled badly with humidity my first winter keeping ball pythons. The enclosure humidity would spike to 80% right after misting and crash to 35% within a few hours. Partially covering the screen top and adding a room humidifier solved the problem almost entirely.
Emergency Preparedness
Power outages happen, and if you live somewhere with harsh winters, you need a plan. Here's mine:
The Emergency Kit
- Chemical hand warmers: The disposable kind that hikers use. They produce heat for 8-12 hours. Wrap one in a sock and place it in the enclosure — never directly against the animal.
- Insulation materials: Blankets, towels, even newspaper can be wrapped around enclosures to retain heat. Styrofoam panels on the outside of glass tanks are incredibly effective.
- Battery-powered temperature monitor: So you know exactly what's happening inside the enclosure even without power.
- A plan for extended outages: Know where you could take your animals if the outage lasts more than 12 hours. A friend's house, a hotel that accepts pets, or even your car with the heater running can be options in a genuine emergency.
After my power outage scare, I also invested in a small uninterruptible power supply (UPS) that can keep a ceramic heat emitter running for a few hours. It's not a permanent solution, but it buys time.
Feeding Adjustments
Even reptiles that don't formally brumate may eat less during winter. Shorter days and slightly cooler ambient temperatures can naturally reduce appetite. This is generally nothing to worry about for healthy adults. Don't try to force-feed or stress about a modest decrease in food intake during the colder months.
That said, make sure reduced eating isn't caused by temperature problems in the enclosure. A reptile that's too cold can't digest properly, so even if it eats, the food may sit in the gut and cause problems. Always verify that your warm side temperatures are in range before attributing reduced appetite to seasonal changes.
Getting Through to Spring
Winter reptile care isn't difficult, but it does require more attention than summer keeping. The core message is simple: monitor temperatures more closely, maintain humidity more actively, prepare for emergencies, and understand whether your species has natural seasonal behaviors that might mimic illness. Do those things, and your reptile will come through winter in great shape, ready to bask in the spring sunshine filtering through the window — even if that sunshine is on the other side of the glass.