Summary of Key Points Core Viewpoint - The article discusses the recent weather conditions in China, particularly focusing on the occurrence of dense fog in several regions, the expected changes in weather patterns, and the implications for air quality and temperature fluctuations. Group 1: Weather Conditions - Multiple regions including Beijing, Tianjin, Hebei, Henan, Shandong, Jiangsu, Anhui, and Hubei experienced dense fog, with visibility dropping below 50 meters in areas like Tongzhou, Dezhou, Shangqiu, Bengbu, and Huainan [1][3] - A red alert for fog was issued in Julu County, Hebei, indicating severe visibility issues [3] Group 2: Future Weather Predictions - Following the fog, the weather is expected to improve due to sunlight and weak cold air, with no significant smog forecasted for the next few days [3] - However, from November 4 to 7, the air quality in North China and the Huanghuai region is predicted to deteriorate again, leading to the return of fog and haze [5] Group 3: Temperature Trends - The temperature in central and southern North China is currently around or above 20°C, marking a recent high [8] - A significant drop in temperature is anticipated next week due to a strong cold air mass, with expected decreases of 4 to 8°C in many areas, and localized drops exceeding 10°C [8] Group 4: Rainfall and Flood Risks - From November 2 to 4, heavy rainfall is expected in the eastern Southwest, central and southern Jiangnan, eastern Guangxi, western Guangdong, and Hainan, with cumulative precipitation reaching 30 to 80 millimeters, and localized areas in Yunnan and Hainan potentially exceeding 200 millimeters [9][13] - The rainfall may lead to significant flooding risks in certain regions, particularly in Yunnan and southern Sichuan, where the rainfall could surpass the total for the entire month of October [13] Group 5: Tropical Weather Developments - The Japan Meteorological Agency has classified a tropical disturbance east of the Philippines as a tropical depression, which is expected to develop into Typhoon "Haigui" by November 5, with potential impacts on the South China Sea [14]

Group 1 - A new cold air mass has arrived, primarily affecting northern regions of China, while southern areas remain warm with temperatures reaching around 30°C in places like Guangdong and Hainan [1][3] - Northern cities such as Changchun and Shenyang are expected to experience their lowest temperatures of the year, with highs of 4°C and 8°C respectively [3] - The overall trend for the coming days indicates a gradual warming in the central and eastern regions of China, with temperatures expected to return to normal or slightly above normal levels after October 28 [3] Group 2 - Fog and haze are anticipated in northern regions during the intervals between cold air impacts, particularly affecting areas like southern Hebei and most of Shandong [5] - Historically, from September to February, northern China experiences a significant number of foggy days, with cities like Shijiazhuang and Tianjin seeing over 80% of their annual fog days during autumn and winter [5] - Snowfall is expected in northeastern Inner Mongolia and northern Heilongjiang due to the new cold air, with localized heavy snow possible [6] Group 3 - The southwestern region of China is forecasted to have frequent rainfall in the last days of October, particularly in areas like Sichuan and Yunnan, with precipitation expected over 4 to 7 days [6]

Summary of Key Points Core Viewpoint - The Central Meteorological Administration forecasts significant cold air impacts across various regions in China, including Inner Mongolia, Northeast China, North China, and the Huanghuai area, leading to strong winds and temperature drops [1][4]. Group 1: Weather Forecast - From October 25 to 26, areas such as eastern and southern Qinghai, northern and eastern Tibet, and central and southern Gansu are expected to experience light to moderate snow or sleet, with some regions facing heavy snow and local blizzards [1]. - Starting today until October 27, cold air will affect central and eastern Inner Mongolia, Northeast China, North China, and Huanghuai, with wind speeds of 4 to 6 levels, gusts reaching 7 to 8 levels, and localized gusts up to 9 levels [4]. - Temperature drops of 4 to 6 degrees Celsius are anticipated in some areas, with local drops exceeding 8 degrees Celsius [4]. Group 2: Visibility and Air Quality - Prior to the cold air impact, areas in North China and Huanghuai will experience fog and haze, with significant visibility reductions in regions such as southern Hebei, southern Beijing, and central Shaanxi [4]. - This morning and into the afternoon, heavy fog is expected in southern Hebei, southern Beijing, and central Guizhou, with visibility potentially dropping below 200 meters in some areas [4].