Incubating eggs can be a tricky business for beginners. There are very specific conditions you need to maintain to ensure the highest hatch rates for your eggs. The window of appropriate temperatures is fairly small.
A temperature that is too cold, or especially one that is too hot, can have significant effects on how many of your eggs hatch. In this article, we’ll take a look at the perfect temperature to keep your eggs at, what can happen if the temperature gets too hot or too cold, and what you can do to ensure a high hatch rate.
Key Points In This Article
The optimal conditions for incubating and hatching chicken eggs involve maintaining specific temperature and humidity levels. Here’s a summary of the optimal conditions:
Maintaining these conditions is essential for achieving a high hatch rate. It’s also important to ensure that your incubator is well-ventilated and that the temperature and humidity are evenly distributed throughout the incubator. Regularly turning the eggs until the last three days before hatching is also crucial for proper development.
| Condition | Temperature (Celsius) | Humidity | Stage of Development |
|---|---|---|---|
| Incubation Temperature | 37.5 to 37.8 | N/A | Day 1 to Day 18 |
| Hatching Temperature (last 3 days) | 37.2 (optional adjustment) | N/A | Day 19 to Day 21 (Hatching) |
| General Incubator Temperature | 37.5 | N/A | Throughout incubation |
| Incubator Humidity | |||
| First 18 Days | N/A | 40-50% RH | Day 1 to Day 18 |
| Last 3 Days (Lockdown Period) | N/A | 65-70% RH | Day 19 to Day 21 (Hatching) |
What Is the Ideal Temperature and Humidity for Hatching Chicken Eggs?
There is a very narrow window for ideal temperature and humidity during chicken egg hatching. That window changes slightly throughout the entire incubation period, which is generally about three weeks or 21 days.
To start with, the temperature of your incubator should be between 99 degrees Fahrenheit and 102 degrees Fahrenheit, or 37 degrees Celsius and 39 degrees Celsius.
Depending, of course, on the unit of temperature your thermometer uses. This temperature should be maintained consistently, generally aiming for an average of 100 degrees Fahrenheit (38 degrees Celsius) for approximately 18 days.
After 18 days, the temperature should be lowered ever so slightly to around 98.5 degrees Fahrenheit or just below 37 degrees Celsius.
The lowered temperature compensates for the increased heat generated by the egg embryos before hatching.
It is never a good idea to aim for higher temperature levels in an attempt to hatch your chicks faster. Patience is required, and you must allow the natural cycle to unfold. Otherwise, you’ll be in for a higher mortality rate when your eggs hatch.
Always aim for the middle of the temperature window, and keep a careful track of the temperature in case of any errors or fluctuations. Also, ensure that your incubator is kept in an area with minimal temperature fluctuations. External temperature fluctuations can significantly affect the sustainability of the temperature in your incubator. Direct sunlight is a no-go, so it’s best to keep your incubator in a shady environment with a stable temperature.
As for humidity, aim to keep the level between 50% and 55% for the initial 18 days. After 18 days, you’ll raise the humidity level to approximately 65% while slightly lowering the temperature. This increased humidity level prevents the chicks from getting stuck on the egg membrane as they begin to hatch.
Humidity can be adjusted by simply placing a container of water below the egg tray and adjusting the ventilation to decrease or increase it until the desired humidity range is reached. Many incubators will also have trays included in the design where water can be added to increase humidity.
How Do I Adjust the Temperature on my Incubator?
Your incubator’s temperature should be controlled by a thermostat, which often consists of a screw that will be turned either counterclockwise to increase heat or clockwise to decrease heat. Incubator’s control mechanisms can vary, though, so be sure to check your instruction manual. Many modern incubators will utilize digital controls, making temperature adjustment significantly easier.
It is essential to set up the incubator and adjust the temperature a few days before placing your eggs, as this allows you to ensure the temperature is stable and adjust for any fluctuations. Once you’ve got the eggs in, be sure to check the temperature and humidity levels several times a day to ensure everything is as it should be.
However, allow a two-day window after first placing the eggs, during which you don’t increase the temperature. This allows the eggs to stabilize to the incubator’s temperature, which can make temperature readings difficult in the first 48 hours. If you’ve properly stabilized the temperature beforehand, things should even out between the eggs and the incubator after a day or two.
Overcompensating and increasing the temperature immediately after placing the eggs can result in the temperature becoming too high right from the start, which will cause your eggs to die on arrival.
Over time, the temperature can rise as the heat from the eggs increases due to the growing embryos, so you’ll need to keep a close eye on the temperature to ensure it never exceeds 102 degrees Fahrenheit or 39 degrees Celsius. Even just a few hours in too cold or too hot temperatures can affect the overall mortality rate of your eggs.
What Temperature Will Kill Chicken Eggs?
High temperatures are much more detrimental to the health of your eggs than cold temperatures, so you should be much more careful about keeping the temperature from getting high than you would be about keeping the temperature from getting cold.
A temperature of 103 degrees Fahrenheit or just over 39 degrees Celsius for just a few hours can drastically increase the mortality rate of your eggs. Likewise, a temperature even higher than that for even just a fraction of an hour may result in only one or two of your eggs hatching, if any.
What Happens If Chicken Eggs Get Too Hot?
If chicken eggs get too hot, they need to be cooled immediately; otherwise, they will likely not hatch. As we mentioned in the previous section, a temperature just slightly higher than the allowed range can result in serious problems after only an hour or two.
Temperatures that greatly exceed 102 degrees Fahrenheit can do even more damage in a shorter amount of time. Be sure to keep a constant eye on the temperature of your incubator and never allow it to exceed 102 degrees Fahrenheit, or even get close to that temperature.
Suppose you’ve discovered that your eggs have been sitting at a temperature over 102 degrees Fahrenheit for any amount of time. In that case, you should immediately attempt to cool them down by removing them from the incubator and placing them in cool water.
If you don’t have a container big enough, you can spray them with a hose. You’ll want to cool the eggs so that the shells are approximately 80 degrees Fahrenheit (27 degrees Celsius). The shells will get cooler faster than the embryos, so aim low. Don’t be too worried about over-cooling, as lower temperatures are not nearly as detrimental as the higher ones.
While cooling off the eggs after they’ve been sitting in higher temperatures for a time isn’t a miracle fix, it’s the best you can do given the situation. The hatch rate will likely have been affected at least slightly, but you’ll still have made it better than it would have been without cooling them down. If you are curious, you can candle your eggs to see if there is any movement inside and also to check for veins.
Candling eggs simply entails illuminating the inside of the egg by placing it on a powerful light source that makes the shell transparent. If the embryo has died, there will be no movement, and the veins will generally disintegrate.
Otherwise, put your eggs back in the incubator and hope for the best outcome when hatching time arrives. Be sure to continue checking the temperature multiple times a day.
Will Eggs Still Hatch If They Get Cold?
Eggs can typically hatch after being in colder temperatures for short periods, but this may still slightly affect the hatch rate. A few hours in more frigid, and sometimes even freezing, temperatures can often have little to no effect on the mortality rate, provided the problem is addressed promptly. Because of this, you shouldn’t be too worried if your incubator gets unplugged or turned off accidentally for only an hour or two. Just plug it back in or turn it back on and everything should stabilize.
The biggest issue that cold temperatures pose to your eggs is that they may crack from freezing. Your egg won’t hatch if it’s broken. If your eggs have been stored in very cold temperatures, it is ideal to let them sit at room temperature for about a day before placing them back in the incubator, as you don’t want any extreme temperature fluctuations to compromise the integrity of the egg.
How Long Can Incubated Eggs Be Cold?
Just a few hours is the safest bet for how long incubated eggs can be in colder temperatures, although the less time, the better. There may be situations in which several more hours can be added to that window with little to no effect on the hatch rate; it all depends on the temperature and the stage of development of the eggs.
As we mentioned, discovering that your incubator has turned off for a few hours at a relatively low temperature isn’t a significant issue. A short period at a lower temperature is unlikely to affect the hatch rate.
However, it’s always best to play it safe and routinely check the incubator’s temperature. Power outages can also be an issue, as in some cases, they can last for several hours or more. Keeping your incubator hooked up to a backup generator is a good solution for this.
