今年下半年第一场大范围冷空气过程来袭 北方气温将大面积创新低

Group 1 - The first significant cold air mass of the second half of the year will impact most of central and eastern China from September 15 to 18, leading to a temperature drop in the northern regions by 4 to 8°C, with some areas experiencing drops over 10°C [3] - The cold air will notably affect the northern regions, where temperatures will reach new lows since the beginning of autumn, prompting residents to switch from short sleeves to warmer clothing [3][5] - Cities like Yinchuan and Hohhot will see maximum temperatures drop to around 20°C on September 16, while Zhengzhou and Xi'an may experience their first full day below 20°C on September 18 [3] Group 2 - Before the arrival of the cold air, southern regions will continue to experience high temperatures, with Nanchang recently setting a record for the most high-temperature days in a year (65 days) [3] - High temperatures will persist in Wuhan and Hangzhou for the next three days, potentially breaking local records for the most high-temperature days in a year [3] - After September 18, the prolonged high-temperature period will come to an end, with cities like Hangzhou and Changsha seeing maximum temperatures drop to 26°C, marking a significant decrease in heat [5]