Every reptile species has its own incubation temperature, medium moisture, and days to hatch, and getting them wrong is the most common reason a clutch fails. This guide gives the settings for six popular species in one chart, then walks through each species with sex-determination facts, setup tips, and a problem-and-fix table.
Treat the numbers as well-used starting points. Stability matters more than hitting an exact figure, and your own records across a few clutches will tell you more than any chart.
Quick answer: Most reptile eggs incubate between about 70°F and 90°F, and each species has its own target. Ball pythons and reticulated pythons run warmest at 88 to 90°F. Corn snakes and bearded dragons sit in the low to mid 80s. Leopard geckos range from 80 to 90°F, and crested geckos run coolest at 70 to 78°F. Keep the medium damp but not wet, keep the temperature steady, and never rotate the eggs.
Reptile Egg Incubation Chart: Temperature, Humidity and Days to Hatch
| Species | Temperature | Incubator humidity | Days to hatch | Clutch size | Sex set by temperature? |
|---|---|---|---|---|---|
| Ball python | 88 to 90°F (31 to 32°C) | 55 to 65% | 55 to 60 | 4 to 8 | No, genetic |
| Corn snake | 80 to 84°F (27 to 29°C) | 60 to 70% | 55 to 65 | 10 to 25 | No, genetic |
| Leopard gecko | 80 to 90°F (27 to 32°C) | 60 to 80% | About 40 to 60 (cooler is longer) | 2 per clutch | Yes, in a non-linear pattern |
| Bearded dragon | 82 to 86°F (28 to 30°C) | 50 to 65% | 55 to 75 | 15 to 25 | No, genetic. Very high heat can reverse sex |
| Crested gecko | 70 to 78°F (21 to 26°C) | 70 to 90% | 60 to 120 | 2 per clutch | No, as far as is known |
| Reticulated python | 88 to 90°F (31 to 32°C) | 60 to 75% | About 80 to 90 | About 10 to 100 | No, genetic |
How to Use This Chart
- Verify temperature with a second thermometer placed at egg level. Built-in displays are often off by a few degrees.
- Prepare the medium by weight. A common starting point is equal weights of vermiculite or perlite and water, for example, 100 g of medium with 100 g of water. It should hold together when squeezed but not drip.
- Do not rotate eggs. Mark the top of each egg with a pencil when you collect it and keep that orientation until hatching.
- Do not mix species in one container. See why below.
Ball Python Egg Incubation: Temperature, Humidity and Days to Hatch
Temperature: 88 to 90°F (31 to 32°C) | Humidity: 55 to 65% | Days to hatch: 55 to 60 | Clutch size: 4 to 8 eggs
Does temperature change ball python sex?
No. Ball pythons (Python regius) determine sex genetically, so you do not choose an incubation temperature to steer the sex ratio. Pick the temperature for hatch success. Sustained heat, sustained cold, and large swings still reduce hatch rates and hatchling quality.
Ball python egg moisture
Run the medium damp, not wet. Many breeders keep ball python eggs slightly drier than corn snake eggs, and a soggy medium with stagnant air invites mold. Use a little less water than you would for corn snakes, and check a hygrometer instead of judging by feel alone.
Setting up for ball python eggs
Choose an incubator that holds 88 to 90°F steadily with adjustable airflow, such as the HovaBator 2370 Reptile Egg Incubator Kit (check current availability) or a DIY build with the IncuKit XL for Reptile Incubators. Put a digital thermometer and hygrometer probe inside the container or medium, not in open air. Ball python eggs often stick together, so leave a clutch attached and keep it in a vented container.
Ball python egg problems and fixes
| What you see | Likely cause | What to do |
|---|---|---|
| Eggs dent or shrivel | Medium too dry for too long | Add moisture to the medium gradually and check it more than once a week. |
| Hatchlings are small or underdeveloped | Low or unstable temperature | Run a 48-hour stability test before the next clutch and check with an independent thermometer. |
| Hatchlings are stunted or fail to pip | Sustained high temperature | If the incubator has been running hot, bring it down gradually, not all at once. |
Corn Snake Egg Incubation: Temperature, Humidity and Days to Hatch
Temperature: 80 to 84°F (27 to 29°C) | Humidity: 60 to 70% | Days to hatch: 55 to 65 | Clutch size: 10 to 25 eggs
Does temperature change corn snake sex?
No. Corn snakes (Pantherophis guttatus) are genetically sexed, so you do not weigh a temperature choice against a sex-ratio outcome. They also tolerate a wider temperature band than most species here. Staying in range still gives the most consistent results and the shortest incubation.
Corn snake egg moisture and clutch size
Keep the medium noticeably moist with no pooling water, a little wetter than for ball pythons. Because clutches run large, plan on several containers per incubator.
Setting up for corn snake eggs
A unit like the HovaBator 2370 Reptile Kit handles corn snake clutches well. Use the fan only as far as it helps spread heat evenly across the containers, and confirm the result with a thermometer. Keep extra incubation medium on hand.
Corn snake egg problems and fixes
| What you see | Likely cause | What to do |
|---|---|---|
| Hatchlings are small or runty | Usually parent size, not incubation, if the temperature checks out | Verify temperature, then look at the size and condition of the breeding stock. |
| Fungal growth mid-incubation | High humidity plus a non-sterile medium | Isolate a few affected eggs and boost ventilation. Widespread mold means fixing the medium before the next clutch. |
| Eggs pip very late or not at all | Temperature ran cooler than intended for too long | Check with an independent thermometer, not just the built-in display. |
Leopard Gecko Egg Incubation: Temperature, Humidity and Days to Hatch
Temperature: 80 to 90°F (27 to 32°C) | Humidity: 60 to 80% | Days to hatch: about 40 to 60 | Clutch size: 2 eggs per clutch, several clutches per season
Does temperature change leopard gecko sex?
Yes. Leopard geckos (Eublepharis macularius) are a classic temperature-dependent species, and the pattern is a curve, not a straight line (Viets et al., 1993). In general, cooler temperatures (around 80 to 82°F) tend to produce mostly females, about 85°F tends to produce a mix, and warmer temperatures (around 88 to 90°F) tend to produce more males. Push well past about 90°F and results swing back toward females, often with weaker hatchlings. Treat these as tendencies, not guarantees, and track your own results across several clutches.
Leopard gecko egg moisture
Humidity needs to run higher than for most snakes because leopard gecko eggs lose water easily. The eggs are small, about an inch long, so use small containers and watch humidity closely.
Setting up for leopard gecko eggs
A digital hygrometer matters more here than almost anywhere else, because humidity drifts fast and the margin is narrow. Bury eggs about halfway into the medium so gas exchange is not cut off. In dry climates, mist the container lid and add a room humidifier if you struggle to hold humidity in range.
Leopard gecko egg problems and fixes
| What you see | Likely cause | What to do |
|---|---|---|
| Hatchlings stuck in the shell | Sustained low humidity left them too weak to emerge | Hard to reverse once it starts. Check humidity more closely on the next clutch. |
| Eggs collapse or shrivel | A multi-day humidity drop | Increase medium moisture and mist the container lid as soon as you notice. |
| Hatchlings are small or weak | Sustained low temperature or, less often, humidity high enough to slow development | Check both temperature and humidity rather than assuming one. |
Bearded Dragon Egg Incubation: Temperature, Humidity and Days to Hatch
Temperature: 82 to 86°F (28 to 30°C) | Humidity: 50 to 65% | Days to hatch: 55 to 75 | Clutch size: 15 to 25 eggs
Does temperature change bearded dragon sex?
Bearded dragons (Pogona vitticeps) have sex chromosomes, so sex is genetic. However, very high incubation temperatures (roughly above 89 to 90°F, or 32°C) can reverse genetically male embryos into females (Holleley et al., 2015). Keep the temperature in range and avoid sustained heat.
Bearded dragon egg moisture and clutch size
As a desert species, bearded dragons need lower humidity than corn snakes or leopard geckos. Clutches run large, so plan for several containers, and note the eggs are bigger than most snake eggs, so a standard small container can feel tight.
Setting up for bearded dragon eggs
The HovaBator 2370 Reptile Kit offers the fan control large clutches need, although with 15 to 25 eggs you will run several containers side by side. Keep extra incubation medium ready.
Bearded dragon egg problems and fixes
| What you see | Likely cause | What to do |
|---|---|---|
| Incubation runs unusually long | Sustained low temperature | Verify with a backup thermometer. |
| Hatchlings are weak or small | Breeding stock condition, if temperature and humidity both check out | Incubation settings cannot fix stock condition. |
| Mold mid-incubation | Bearded dragon eggs are sensitive to high humidity | Increase ventilation and cut medium moisture at the first sign. |
Crested Gecko Egg Incubation: Temperature, Humidity and Days to Hatch
Temperature: 70 to 78°F (21 to 26°C) | Humidity: 70 to 90% | Days to hatch: 60 to 120 | Clutch size: 2 eggs per clutch
Does temperature change crested gecko sex?
No, as far as is known. Crested geckos (Correlophus ciliatus) are not temperature-sexed, so most breeders do not weigh sex ratio when choosing a temperature within range.
How to incubate crested gecko eggs at a cool temperature
Crested geckos need a much cooler, more humid environment than most incubators are built for, and standard tabletop units usually cannot hold a temperature below the mid-70s because they add heat but cannot remove it. A few approaches work:
- Room temperature: if a room stays reliably between about 68 and 75°F, such as a cool basement, eggs can often incubate in a covered, humid container with no heat source.
- Thermostat-controlled setup: let the room's coolness keep the chamber from running too warm and add only a little controlled heat.
- Cooler-based DIY box: an insulated box with active temperature control is more advanced and not the easiest place to start.
Keep the medium consistently moist without pooling water, and make sure the container has ventilation.
Crested gecko egg problems and fixes
| What you see | Likely cause | What to do |
|---|---|---|
| Incubation runs much longer than expected | Average temperature has drifted below target | Development slows toward the cool end of the range. Check the average, not one reading. |
| Mold develops | Stagnant air, more than the moisture level | Add ventilation holes and make a small cut to medium moisture. |
| Eggs shrivel | Humidity too low, or temperature creeping too high | Check both. Either increases water loss. |
Reticulated Python Egg Incubation: Temperature, Humidity and Days to Hatch
Temperature: 88 to 90°F (31 to 32°C) | Humidity: 60 to 75% | Days to hatch: about 80 to 90 | Clutch size: about 10 to 100
Why reticulated python eggs are an advanced project
Reticulated pythons (Malayopython reticulatus) are a step up in cost and risk. Breeding stock is often a serious investment, and clutches can be far larger than those of other species here, sometimes requiring more than one incubator. They are also sensitive to temperature fluctuations. Some breeders link sustained swings to developmental problems in hatchlings, though no precise figure is established. This is not the species to trust to a budget incubator with unverified stability. Like ball pythons, they are genetically sexed.
Setting up for reticulated python eggs
Given the egg size and clutch volume, consider the IncuKit XL for Reptile Incubators, which is built to convert a larger cabinet rather than rely on a small tabletop chamber. Check temperature and humidity every day, and consider a battery backup given how much is riding on stable power.
Reticulated python egg problems and fixes
| What you see | Likely cause | What to do |
|---|---|---|
| Temperature spikes and drops | A thermostat not holding calibration | Verify stability with an independent thermometer before trusting a valuable clutch to the setup. |
| A meaningful share of eggs fail to develop | Breeding stock fertility, or conditions in the first days after laying | Candle earlier rather than later to catch problems sooner. |
How to Set Up a Reptile Egg Incubator
- Assemble the incubator as the manual says, and confirm the thermostat probe is seated correctly before you power on.
- Prepare the medium for your species, using about equal weights of vermiculite or perlite and water as a starting point, then let it sit for a couple of hours so moisture distributes evenly.
- Calibrate the temperature. Compare an independent thermometer against the unit's display at your target setting and adjust.
- Place the hygrometer probe in the container or medium, not in open air away from the eggs.
- Run a 48-hour stability test before adding eggs, and fix any wide, sustained temperature spread first.
- Add the eggs without rotating them, mark the top of each, and start a simple log of date, temperature, humidity, and notes.
For a copy-ready log and more on troubleshooting, see our guide to preventing common problems in reptile egg incubation.
Equipment for Reptile Egg Incubation
| Product | Best for | Good to know |
|---|---|---|
| IncuKit XL for Reptile Incubators | Large clutches and DIY builds, such as reticulated pythons | Thermostat, heater, and recirculating fan for a box or cabinet you provide. Thermostat range is listed as 60 to 104°F. |
| HovaBator 2370 Reptile Kit | Snakes, lizards, and geckos in a ready-made unit | Digital thermostat, adjustable fan, four substrate cups, hatching grid, and hatching medium. Check current availability. |
| Hova-Bator Genesis 1588 | Species in the 80°F and above range | Adjustable down to 80°F, and the fan can be turned off. |
| Reptile Egg Incubation Substrate Accessory Pack | Any species | 9 oz hatching substrate and four bowls with vented lids. |
| IncuTherm Plus Hatch Monitor | Checking temperature and humidity at egg level | Remote probe, high and low memory, calibrated to within 1°F. |
See all reptile incubators, or read our best reptile egg incubator guide and reptile egg incubator buyers guide to compare options.
Why You Shouldn't Mix Species in One Container
A ball python clutch and a corn snake clutch need temperatures roughly eight to ten degrees apart. Even in separate containers inside one incubator, temperature gradients are rarely consistent enough to keep both species in range. If you breed more than one species, use a separate incubator for each, or a single unit with genuinely independent zones.
If the Power Goes Out or You're Away at Hatch Time
Early in incubation, most reptile eggs tolerate a short outage of a few hours with little consequence, especially if you wrap the incubator in towels or blankets to slow heat loss. Later on, the same outage matters more: a sustained drop to room temperature for several hours can delay hatching by a few days, though it does not necessarily mean the clutch is lost. A battery backup is worth it if outages are common, especially for large or valuable clutches.
If you will be away during an expected hatch, know that pipping is usually gradual, often a day or more from the first hole to full emergence, and hatchlings typically have reserves to wait in the shell after pipping starts. Raise humidity slightly heading into the expected window, and have someone check the incubator if you can.
Species Difficulty at a Glance
| Species | General difficulty | Why |
|---|---|---|
| Corn snake | Easier | Not temperature-sexed, tolerates a wide temperature band, widely available |
| Ball python | Moderate | Needs steady temperature and a slightly drier medium than corn snakes |
| Bearded dragon | Moderate | Large clutches and longer incubation add logistical work |
| Leopard gecko | More involved | Temperature-dependent sex, close humidity monitoring, small eggs |
| Crested gecko | More involved | Needs an unusually cool, humid setup most incubators are not built for |
| Reticulated python | Advanced | Large clutches, high-value stock, low tolerance for instability |
This is a general impression, not a strict ranking. A careful first-time breeder with corn snakes and a careless one with any species can end up in very different places.
Reptile Egg Incubation FAQs
What temperature should reptile eggs be incubated at?
It depends on the species. Ball pythons and reticulated pythons are usually held at 88 to 90°F, corn snakes at 80 to 84°F, bearded dragons at 82 to 86°F, leopard geckos at 80 to 90°F, and crested geckos at 70 to 78°F. Whatever you choose, keep it steady, because swings cause more losses than a small error.
What humidity do reptile eggs need?
Most reptile eggs need a damp, not wet, incubation medium. A common starting point is equal weights of vermiculite or perlite and water. Typical incubator humidity runs about 50 to 65% for bearded dragons, 55 to 70% for most snakes, 60 to 80% for leopard geckos, and 70 to 90% for crested geckos.
How long do reptile eggs take to hatch?
Roughly 40 to 120 days depending on species and temperature. Typical figures are 55 to 60 days for ball pythons, 55 to 65 for corn snakes, 40 to 60 for leopard geckos, 55 to 75 for bearded dragons, and 60 to 120 for crested geckos. Warmer temperatures within range shorten incubation.
Does temperature determine the sex of reptile hatchlings?
Only in some species. Leopard geckos have temperature-dependent sex determination, with a non-linear pattern. Ball pythons, corn snakes, reticulated pythons and crested geckos are not temperature-sexed. Bearded dragons are genetically sexed, but very high incubation temperatures can reverse genetic males into females.
Can I incubate different reptile species in the same container?
No. Species need different temperatures and moisture levels. A ball python clutch and a corn snake clutch need temperatures roughly eight to ten degrees apart. Use a separate incubator for each species, or a unit with truly independent zones.
Do I need a hygrometer for reptile egg incubation?
Yes. Judging the medium by feel is much less reliable than a digital reading, especially for species with a narrow humidity window. Place the probe inside the egg container or medium, not in open air, and check it against a second device or a salt test.
Can I use a poultry incubator for reptile eggs?
You can try, but many poultry incubators run too warm, have strong fan circulation, and cannot hold low temperatures. Pick a unit with an adjustable thermostat and fan control. Expect lower hatch rates than with a reptile-appropriate setup, and verify temperature with an independent thermometer.
Should I rotate reptile eggs?
No. Once the embryo attaches to the inner shell membrane, rotating the egg can kill it. Mark the top of each egg with a pencil when you collect it, and keep that orientation through to hatching.
What temperature should I incubate crested gecko eggs at?
About 70 to 78°F. Most heated incubators struggle to hold temperatures this low, so many breeders use a cool room, a thermostat-controlled setup that adds only a little heat, or a cooler-based DIY box. Keep the medium consistently moist and the container ventilated.
Which reptile eggs are easiest to hatch for beginners?
Corn snake eggs are the most forgiving. They tolerate a wider temperature band, are not temperature-sexed, and clutches are large. Ball python eggs are moderate. Leopard and crested gecko eggs need closer monitoring, and reticulated python eggs are an advanced project.
How can I tell if reptile eggs are fertile?
Candle the egg gently with a bright, cool light without rotating it. A network of pink or red veins, or a visible embryo, means it is developing. An even yellowish glow with no veins after enough time usually means it is infertile. Wait before discarding, because some eggs look poor but hatch.
How long do hatchlings stay in the egg after pipping?
Often a day or two. Reptile hatchlings usually slit the shell, then rest with their head out while they absorb the yolk. Do not pull them out. Keep humidity steady, keep the incubator closed, and only seek help if a hatchling is clearly stuck for several days.
What happens if the power goes out during incubation?
Early in incubation most eggs tolerate a short outage of a few hours, especially if you wrap the incubator in towels. Later, a sustained drop to room temperature can delay hatching by a few days. A battery backup is worth it if outages are common where you live.
More help: reptile incubation time and temperature chart, preventing common reptile incubation problems, and how to lower humidity in an incubator.
Sources and Further Reading
- Viets, B.E., Tousignant, A., Ewert, M.A., Nelson, C.E., and Crews, D. (1993). Temperature-dependent sex determination in the leopard gecko, Eublepharis macularius. Journal of Experimental Zoology, 265(6), 679-683.
- Holleley, C.E., et al. (2015). Sex reversal triggers the rapid transition from genetic to temperature-dependent sex. Nature, 523, 79-82.
- Association of Reptilian and Amphibian Veterinarians (ARAV)
Last updated November 2026. Temperatures, humidity, and incubation times are common starting points reported by breeders and research for these species. Consult species-specific research or an experienced breeder for your particular line before making breeding decisions based on temperature. Product availability and prices change, so confirm current details on each product page before ordering.
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