The ideal temperature and humidity for hatching chicken eggs are critical factors that can affect the success of the hatch. The suggested guidelines for temperature and humidity are as follows:

• Optimum temperature: 100.5 degrees Fahrenheit or 37.7 degrees Celsius.
• Temperature range: 99-102 degrees Fahrenheit or 37.2-38.9 degrees Celsius.
• Relative humidity, day 1-17: 50-55% .
• Equivalent to a wet bulb temperature of 85-87 degrees Fahrenheit or 29.4-30.6 degrees Celsius.
• Relative humidity, day 18-21: On day 18, raise the relative humidity to 70% .
• Use a hygrometer to ensure humidity levels are correct throughout the incubation period.
• Only open the incubator when necessary – doing so can let heat and humidity escape and can affect the success of the hatch.

It is important to note that the temperature and humidity levels may vary depending on the breed of chicken and the type of incubator used. It is recommended to monitor the temperature and humidity levels closely throughout the incubation period and adjust them as needed to ensure the best possible hatch rate.