Why is the air in Kunming so dry?

"The existence of the south branch jet of the westerly wind in winter has a lot to do with the winter weather in the southern half of China. It comes from the arid areas of Arabia, Iran and northern Pakistan, and the lower layer is dry and hot, forming the dry season of Yunnan Plateau. But at an altitude of 3 thousand meters, it is warm and humid. In addition, the polar continental air mass from the north becomes weaker and wetter. In this way, the two kinds of airflow meet in Kunming area and become semi-static, which is called quasi-static front stop in Kunming. The front west is controlled by a single southwest airflow, and the cloud system is difficult to develop, mild and sunny, with less precipitation and large daily temperature difference. In Fengdong's Guizhou Province and southern Sichuan, the cloud system is developed, the rain is continuous, and the daily temperature difference is small, which is just the opposite of the weather in Kunming. "

"There is little difference between cold and warm seasons in Kunming, but the dry and wet seasons are very clear. From 1 1 to April of the following year, the rainfall was only 100 mm, and the climate was relatively dry. "

"Yunnan is located in the low-latitude plateau, with a special geographical position and complex terrain. Due to the influence of atmospheric circulation, winter is controlled by dry continental monsoon, and summer is dominated by humid maritime monsoon, which belongs to low latitude mountain monsoon climate. "

"In everyone's impression, Kunming is an out-and-out greenhouse, and the annual and daily temperature differences are always small. But there is a temperature difference in Kunming that is difficult for outsiders to understand: the temperature difference between places with the sun and places without the sun.

It seems that this is not easy for people in Sichuan Basin to understand. The humidity is too high, the sun is definitely not very spicy, no matter where it is, it is the temperature. Kunming is different. For example, in winter, in a backlit room, the room temperature is generally less than 10 degrees, and I often get frostbite in such an environment. When you walk out of the room and into the sun, you will feel the rebirth of summer. If you are only outdoors, wearing TS is enough. It's not winter yet, because the temperature in the weather forecast I saw these two days is too strange, so I thought of this. The highest temperature is 25 degrees. Cool, isn't it? You won't think so if you exercise in the sun. This 25 degree was measured in the shade. A sudden rain can push the temperature to a minimum and make you feel the sudden arrival of late autumn. This is the result of the interaction between plateau climate and air drying. "