体感入冬、气象入冬、节气立冬，冬天到底来了没有？

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]