Why is the winter temperature in Xishuangbanna higher than that in the same latitude?

Xishuangbanna is located at the southernmost tip of Yunnan Province, with the Lancang River running through the whole territory, and its altitude is lower than other places in Yunnan. There is a large area of Yunnan-Guizhou Plateau in the north, and the Hengduan Mountains block the cold air in the north, so the winter temperature here is relatively high, showing a state of transition from subtropical climate to tropical rainforest or tropical monsoon climate.

Compared with Fujian, Guangdong and Yunnan-Guizhou Plateau, the barrier of Hengduan Mountains to cold air mass is much stronger than that of Nanling-Wuyishan defense line.

At the same time, because the Lancang River basin is open to the south, this means that when the continental high pressure weakens in winter, the south branch of the westerly belt enters the Indian Ocean, and after being heated and humidified, it goes north. The first stop into China is Xishuangbanna, which is hard to be attacked by cold air. At the same time, the warm and humid air flow takes the lead in visiting here in winter, bringing about warming and precipitation. Of course, the temperature is higher than that in Guangdong, Guangxi and Fujian at the same latitude.

In addition, even without the southern branch season, cold air finally succeeded in crossing the sky and invading here. Because it is the leeward slope of the northeast wind, the cold air in the distance soon becomes dry, the weather is fine and the temperature rises rapidly.

This shows that 1, the terrain on the north side of Xishuangbanna effectively blocks the invasion of cold air; Even if cold air can invade here, the impact time is short and the degradation is fast; The first stop of warm and humid air flow back to the southern sky in winter is Xishuangbanna, which shows that the winter temperature in Xishuangbanna is higher than that in Guangdong and Fujian at the same latitude.

But looking around the world, the temperature in Xishuangbanna will still be lower than that in some tropical desert areas on the west coast of the mainland and in winter in India.