This is a older post that has been resolved but with the inkbird ITC-306A you can actually set it in Fahrenheit to only have half of a degree of difference from it turning on/off. Although on mine I sometimes see it drop a little below the on value and a little above the off value so it's range is slightly more than half of a degree in reality. I had read that some of the other inkbirds you get a smaller fluctuation by using degrees Celsius instead.If I remember correctly Celsius is accurate to within 1 degree and fahrenheit 3 degrees maybe?.
Maybe not. There is nothing in the literature about accuracy. But, if it were off by 1degree in C, it would be off two to three in F. Thus, F temps would actually be more accurate.