During Melbourne's heatwave of 3 consecutive 43 degree plus days in succession a few weeks back the temperature gauge on my Euro would not go any higher that 37. A couple of Saturdays ago when we had the the 47 degree day which sparked the bushfires it wouldn't go any higher than 38. That said, outside of extreme weather conditions I have found that it is usually quite accurate when you compare it to the weather updates on the radio etc.