You might be surprised. I've seen up a 2 degree difference inside of an incubator.My thermo
I only had one thermometer inside and it said 101 plus or minus a few tenths, and same down to 100. Same as the incubator, but I had the thermometer in the middle and these eggs, if I’m guessing correctly, were all to the right side. So guessing cold spot, but it couldn’t have been that different because it’s a pretty small incubator (13 chicken eggs).