Incubating

For a still air incubator, you want the temperature at 101. If you have a fan in your incubator, reduce the temperature to 99.5. Of course, to be this precise you also want to make sure your thermometer is reading accurately. Many a person has incubated keeping the temp at exactly the correct setting, only to find it was 5 degrees off one way or the other.

For humidity, there is greater variability. The main thing is that you want the eggs to evaporate just enough but not too much. For that, 35-40% during incubation works for most people, increasing to 65-70% during incubation and hatching. Again, calibrating your hygrometer prior to starting is crucial to knowing what your actual humidity is, not just what the hygrometer is reading.