The ideal temperature for incubating chicken eggs is between 99 and 102 degrees Fahrenheit (99.5 is often considered to be ideal) . The temperature should be measured at the top of the eggs, and the thermometer should be placed in the middle of the incubator near the eggs on the screen, not under the screen or at the sides of the incubator. The temperature range is 99-102 degrees Fahrenheit, and it should not drop below 99 degrees Fahrenheit or exceed 102 degrees Fahrenheit for more than a few hours. For a still air incubator, the recommended temperature is 38.0°C to 38.6°C (100.5°F to 101.5F) . The temperature inside the incubator should be consistent, and it is important to check the thermometer with a medical thermometer placed nearby to ensure the gauge is working properly.

It is also important to maintain the humidity inside the incubator. The suggested humidity range is 50-65% relative humidity, with 60% often considered the ideal. For the first 18 days, the eggs should be turned or rotated regularly, and the incubator should be kept at a consistent temperature and humidity. On day 18, the eggs should be stopped from turning, and the larger end of the egg should face up. At this point, the temperature should be maintained at 100.5 degrees Fahrenheit, but the humidity should be increased to 70% .

In summary, the ideal temperature for incubating chicken eggs is between 99 and 102 degrees Fahrenheit, and the humidity should be maintained at 50-65% relative humidity. It is important to check the thermometer and maintain a consistent temperature and humidity throughout the incubation process.