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].

Group 1 - The summer solstice on June 21 was celebrated by people in multiple countries, with various activities such as watching the sunrise, singing, dancing, and seal hunting [1][3] - Approximately 25,000 people gathered at Stonehenge to witness the sunrise, breaking previous attendance records, while over 400,000 watched the event online [1] - Greenland has designated June 21 as "Island Day" since 1985, featuring celebrations that include visiting friends and communal meals [1] Group 2 - A seal hunting competition took place in Greenland, where participants brought back seals, with the meat donated to a nursing home and other parts used for clothing [3] - In Ukraine, hundreds participated in traditional dances and games near a folk museum, culminating in a bonfire celebration [3] - The southern hemisphere experienced the winter solstice on the same day, with Bolivia celebrating the Andean New Year through rituals and offerings [3]