Core Viewpoint - The onset of winter has been perceived earlier this year in northern China, particularly in Shanxi province, due to a significant drop in temperatures and continuous rainy weather since October, leading to early heating supply in Taiyuan [1][4]. Group 1: Weather Conditions - Northern regions of China, including Shanxi, have experienced continuous rainy weather and a sharp decline in temperatures since October [1]. - Taiyuan began its heating supply on October 19, more than ten days earlier than the same period last year [1]. - The minimum temperature in southern Beijing dropped below freezing on October 20, prompting public comments about an abrupt transition to winter [1]. Group 2: Meteorological Definitions - The term "入冬" (entering winter) is defined meteorologically as the first day when the sliding average temperature falls below 10 degrees Celsius [3]. - "立冬" (Beginning of Winter) and "冬至" (Winter Solstice) are traditional solar terms, with "立冬" fixed around November 7 or 8, and "冬至" marking the shortest day of the year [3]. Group 3: Perception of Cold - Residents in Taiyuan report feeling a stark cold, with comments on the biting wind and sudden temperature drop [4]. - Meteorological experts indicate that while some areas may feel like winter has arrived, actual winter conditions are not met in Taiyuan, where temperatures are expected to remain above 10 degrees Celsius in the coming days [5]. - The discrepancy between perceived and actual temperatures is attributed to factors such as wind speed, humidity, and sudden changes in weather patterns, leading to a psychological feeling of "winter" despite meteorological definitions [6].

Core Viewpoint - The article discusses the early onset of winter in northern China, particularly in Shanxi province, where temperatures have dropped significantly, prompting early heating measures in cities like Taiyuan. The perception of an abrupt transition from autumn to winter is highlighted, along with the meteorological definitions of winter onset. Group 1: Weather Conditions - Northern China has experienced continuous rainy weather and a sharp drop in temperatures since October, leading to early heating measures in Taiyuan starting on October 19, over ten days earlier than last year [1] - The minimum temperature in Beijing's southern suburbs fell below freezing on October 20, with many residents expressing that it feels like "instant winter" this year [1] Group 2: Meteorological Definitions - The article explains the difference between meteorological winter onset, which is defined by a stable average temperature below 10 degrees Celsius, and the traditional solar terms of winter, such as "Lidong" (立冬) and "Dongzhi" (冬至) [3][5] - In Taiyuan, the upcoming days are expected to have maximum temperatures exceeding 10 degrees Celsius, indicating that it does not meet the meteorological criteria for winter onset yet [5] Group 3: Perception of Temperature - The article notes that the feeling of cold experienced by residents is influenced by various factors such as wind speed, humidity, and clothing, leading to a discrepancy between actual temperatures and perceived cold [6] - The abrupt transition from warmer autumn temperatures to around 10 degrees Celsius contributes to a heightened perception of an early winter, creating a psychological effect of a "cliff-like drop" in temperature [6]