I'm in a very good mood at the moment, so I will answer you It's because kernel changed the way of reporting temperature. Previously, when software (the app you are using) was reading temperature, it was already in grades of Celsius, so if it read "30" it meant 30 grades of Celsius. But now, new kernel changed reading so be more accurate, it now reports temperature in 0.1 grades of Celsius. So if you see 298 grades it/s in fact 298*0.1 = 29.8C. Wait for developers of apps to update them, because it's a bug in app you are using now What's the name of app by the way?