Why are official temperatures recorded in the shade?
Sunlight hitting a thermometer warms up the thermometer itself. The reading would tell you how warm the thermometer is, but not give you the temperature of the air around the thermometer. Meteorologists need the air’s temperatures for the calculations they do to forecast future weather. Our complete answer to your question has a lot more detail on why this is the case. (Answered by Jack Williams, USATODAY.