冷空气已启程！下周降温可直达南方，这些地方多雨状态或持续一周

Group 1 - A strong cold air mass is affecting China, leading to significant temperature drops in the northern regions, with temperatures expected to fall by 4 to 8 degrees Celsius, and in some areas by more than 10 degrees Celsius [2][4] - The highest temperatures in northern regions will drop below 20 degrees Celsius for the first time since the beginning of autumn, particularly in cities like Changchun, Hohhot, and Zhengzhou [2][4] - The cold air will also push the autumn process forward in the North China Plain, with cities like Beijing, Tianjin, and Shijiazhuang likely to officially enter autumn next week [4] Group 2 - The southern regions, particularly southern Jiangnan and South China, will experience limited effects from the cold air, with maximum temperatures remaining around 32 degrees Celsius, indicating persistent heat [6] - Heavy rainfall is expected in the southwestern to Huanghuai regions, particularly in areas like the Sichuan Basin and the Shaanxi-Sichuan border, where extreme rainfall may occur [7][9] - The rainfall will be continuous, with significant precipitation expected from the 15th to the 21st, leading to potential secondary disasters such as flash floods and landslides [9][10]