I have two Accurites and one different brand. All three are about the same.....usually 1-2% off on the humidity and 1-2 degrees off on temp. I just checked my snake room (I rotate the thermometers in and out of different tubs) and all three temps were at 82, the bottom rack "outdoor" probe was at 81, and the other brand was at 55% humidity, and the Accurites were at 57% and 59% humidity.

I bought 10 of those aquarium thermometers (all the same exact brand you see at Petco....sometimes in yellow but usually small with a probe). I put all ten of them in one tub and 3 of them were in the 83's, three of them were right at 81, and the rest were 78-81. There was a good 4 degree, give or take difference. My Accurites are more for a guide I guess. As long as the temps are 80-83ish on the cool side and humidity is between 50-65%.