model 01531Dl. In Sept 2017 I purchased an AcuRite Professional Weather Center. Immediately I noticed higher high temps (out doors) on sunny, calm days than those detected on other AcuRite and non AcuRite termometers with sending units mounted in the shade and media units. No that it is summer these differances are as much as 10-12 degres on sunny, calm days and as little as 1-2 degrees on cloudy days. Also, sunny, windy days, differances of 5-8 degrees. Low temps are within 0-2 degrees. Could the solar powered internal aspirating fan not be working? Should you be able to hear the fan running? I can not!