今天进四九了

Group 1 - The core viewpoint of the article highlights that the cold weather during the "Four Nine" period will be significantly harsher than that of "Three Nine" [1] - A strong cold air mass is expected to impact most regions of China from January 17 to 21, with temperatures dropping by an average of 10°C [1] - In areas such as the Huai River basin and the middle and lower reaches of the Yangtze River, the cumulative temperature drop may exceed 20°C, leading to rapid freezing conditions in cities like Zhengzhou, Wuhan, Nanjing, and Hefei [1] Group 2 - The article notes that from January 19 to 20, there will be widespread rain and snow, causing a stark contrast in temperature perception from previously warm conditions to damp and cold [1] - The significant temperature drop and accompanying weather changes necessitate that individuals take precautions to stay warm [1]