Hiding in the screen of glass thermometer

Why every time the weather forecast at the highest temperature, I always feel that the actual situation is far more than the temperature? I think we usually temperature for weather forecast, there is this feeling, so the data of the meteorological station, what was it? In fact, the observatory under the state of nature is the highest temperature of air flow temperature, also is the standard temperature, is measured in the screen. But in general, the screen is in direct sunlight, wind, rain, wind good lawn, is 1 from the ground. 5 meters distance. According to the world meteorological organization of uniform standards, the thermometer should be placed in the screen, in other words, in the measurement of the thermometer screen environment, than the people walking in the street environment is much better, so you feel the temperature far more than the data broadcast out, is this truth. The meteorological observation, why do you want to paint the thermometer in the white screen? （ 1) Prevent sun direct illuminate glass's capacity to absorb radiation from the sun is bigger than air, therefore, under the sunlight insolate directly, the thermometer readings is higher than the temperature of the air around it. In order to make the thermometer can prevent the sun, and can prevent the wind rain, which can accurately measure the temperature, will put the thermometer in the shade. Screen painted white, inside and outside, onto the most sunlight is reflected on the screen, the air in the cabinet not higher because of the temperature of the walls, so to measure the temperature is accurate. （ 2) Reduce air flow disturbance to the temperature measurement. We measured the temperature is not affected by the sun direct illuminate the free flow of air temperature. Why the screen door toward the northern cape? Prevent sun direct illuminate in the screen. Why the screen above the ground is usually 1. 5 meters? At this altitude atmospheric change is stable, and the height is the height of human activities, usually has more practical value.