There are a couple of things you need to make sure about: Firstly, use a good quality calibrated thermometer when measuring the temperature. If you use a thermometer of poor quality, you might get incorrect readings. Secondly, measure the temperature at the eggs. This is the only temperature that really counts. Make sure your the temperature is consistent where the eggs are. If you are experiencing humidity problems consider making use of the humidity pads inside the incubator. This will lead to a more consistent humidity. Remember that outside humidity can also effect the humidity on the inside of the incubator, so try and regulate the outside humidity as well if possible. Finally, I would not be too overly worried about the difference in temperatures. If it was a great difference, like 5 degrees, I would be worried. However, if the difference is 1 degree, I would not be too concerned.