Why does China become the coldest country in the same latitude in the world in winter?

The cold wave and strong wind stopped in winter, and the weather gradually warmed up under the warm sun, but the good times did not last long. Often the second cold wave goes south one after another, and the temperature drops sharply. If the daily average temperature is plotted into a curve in turn, the shape of the curve is like waves of the sea or steep peaks. It can be seen that the winter in our country is particularly cold, mainly because of the cold wave and cold air that often blows from the north in winter. If there is no cold wave going south and the temperature reaches the zonal average, Harbin will be as warm as Xuzhou and Zhengzhou, Beijing will be warmer than Nanchang and Changsha, and Shanghai will be as warm as Nanning and Guangzhou, and there will be no winter!

Where do these cold waves come from? They are from Siberia in the Soviet Union. Some cold waves also come from the Arctic Ocean, but they also pass through Siberia. Siberia is the coldest place in the northern hemisphere in winter. In Yansk, Oymyakon and Vilho in the Arctic Circle, the average temperature in June is nearly -50℃ at 5438+ 10, and the absolute minimum temperature is as low as -72℃. This cold air blows to our country (although the temperature rises along the way under the baking of Levin and warm land), and it certainly makes the eastern part of our country become the "champion" of low temperature at the same latitude. However, the southwest of Sichuan Province and most parts of Yunnan Province in China are in the dry and warm southwest westerly airflow from southwest Asia in winter, and the climate is very warm: the average temperature in Kunming 10/0 at an altitude of1m is as high as 7.8℃, and the latitude with the east is only 1 167 m, but in Guilin. Another example is Yuanmou in the dry-hot valley of Jinsha River in Yunnan, where the altitude is 1 18m. In June, the temperature was as high as 15.5℃ in 5438+1October, but it was 9.7℃ higher than that in Linxian County, Hunan Province, where the altitude at the same latitude was only 185m. However, we should know that in winter, the temperature in South China will drop by 4 ~ 5℃ on average for every increase of 1km.