据苏州市气象台最新预测，新的一周除20日夜里至21日白天有一次降雨过程外，其余时段以云系变 化为主。气温方面，周中前期气温有所回升，周后期受冷空气影响，气温下降，周最低气温0℃左右， 出现在15日早晨。 随着干冷气团迅速占据主导，苏城14日天气转好，气温继续下滑，全天依然维持在个位数，西北风 有所减小。冷空气叠加夜间晴空辐射降温影响，本次过程苏城气温最低谷出现在15日早晨，仅0℃左 右。寒潮影响趋于结束，短期内苏城气温逐渐回升，最高气温又将升至10℃以上，这次能否满足连续5 天滑动平均气温低于10℃这一入冬标准，市民可继续关注。 上周末之前，下半年苏城已先后出现两次寒潮过程。两场寒潮来势汹汹，影响时间不长，过境后苏 城气温回升较快，两次入冬尝试均以失败告终。而随着冷空气主体的逐渐远离，苏城14日天气转好，风 力已明显减小，但气温仍在继续下降，阳光虽已返场，但升温幅度有限，寒意袭人。 受寒潮影响，苏城上周末天气大变样，气温断崖式下跌。21日将进入冬至节气，之前的两场寒潮均 未能敲开冬天的大门，"入冬困难户"这回能不能摘帽呢？ ...

据苏州市气象台最新预测，新的一周苏城除12月2日夜里有弱降水，其余时段以云系变化为主。12 月2日夜里至3日受冷空气影响，偏北风力较大。周前期受冷空气影响，气温逐步下降，周后期气温有所 回升，周最低气温0℃至零下1℃，出现在12月4日早晨。目前来看，预计苏城12月上旬降水量较常年仍 异常偏少，旬平均气温与常年相近。 近期冷空气频频影响，苏城气温起伏不定，目前仍未达到连续5天滑动平均气温＜10℃这一入冬标 准。 处于冷空气间歇期，上周末的苏城沉醉在了深秋的暖阳里，最高气温爬升到了22℃以上，白天暖意 融融。12月7日将进入大雪节气，持续晴朗干燥的天气格局几时打破，秋冬转换的进程几时重启呢？ ...

Core Viewpoint - The article discusses the impact of a strong cold air mass sweeping across China, leading to concerns about the upcoming winter temperatures and the characteristics of seasonal temperature fluctuations in the context of global warming [1][3]. Group 1: Winter Temperature Predictions - The National Climate Center predicts that this winter, temperatures in China will be close to or slightly warmer than the historical average, but with significant fluctuations between cold and warm periods [1][3]. - The warming trend in winter temperatures is evident, with the Arctic experiencing a more pronounced temperature increase compared to tropical and subtropical regions, leading to more extreme temperature variations in China [3]. Group 2: Seasonal Changes - The transition from autumn to winter is typically rapid in many regions of China, contributing to the perception that autumn is shorter [4][7]. - Statistical data indicates that autumn has indeed shortened in many cities, particularly in eastern regions, with cities like Hefei, Guangzhou, and Nanning experiencing a reduction of over 10 days in autumn length compared to historical data [9]. Group 3: Overall Seasonal Length Trends - Despite the perception of a longer winter, most regions in China are experiencing a shortening of winter length due to climate change, with a slight delay in the onset of winter and an earlier arrival of spring [11].

Core Points - A strong cold air mass is expected to impact China from October 16 to 21, leading to the lowest temperatures of the second half of the year in most regions [1][3] - Beijing is forecasted to experience a significant drop in temperature, with nighttime temperatures falling to single digits starting from October 17, and potentially reaching around 2°C on the night of October 19 [1][3] - This cold air mass is considered the strongest of the second half of the year, with a prolonged impact and significant temperature drops [5] Summary by Sections Weather Forecast - The cold air mass is expected to lead to continuous average daily temperatures below 10°C in Beijing from October 18 to 24, indicating an early onset of winter [3] - The average winter onset date for Beijing is typically October 31, based on historical data from 1991 to 2020 [3] Temperature Impact - Northern regions will experience persistently low temperatures, with areas like North China and eastern Huanghuai expected to have average temperatures below 10°C for five consecutive days starting October 18 [5] - Initial frost is anticipated in northern China, including regions like Liaoning [5] Weather Warnings - Beijing's meteorological authority has issued blue alerts for cold waves and strong winds, warning of temperature drops of around 8°C and nighttime lows of about 4°C in plain areas [5] - Frost warnings have been issued for several districts, indicating potential agricultural impacts due to low temperatures [5] Health Advisory - The Beijing Center for Disease Control advises the public to take precautions against the cold, including wearing appropriate clothing and maintaining good hygiene practices to prevent respiratory illnesses during the flu season [6]

Core Points - A strong cold air mass is affecting China from October 16 to 21, leading to the lowest temperatures of the second half of the year in most regions [1][2] - Beijing is expected to experience a significant drop in temperature, with nighttime temperatures falling to single digits starting from October 17, and potentially reaching around 2°C on the night of October 19 [1][2] - The cold air mass is described as the strongest of the second half of the year, with a long duration and significant temperature drop [2] Summary by Sections Weather Impact - The cold air mass will result in continuous average temperatures below 10°C in Beijing from October 18 to 24, indicating an early onset of winter compared to the average date of October 31 [1] - Northern regions, including parts of North China and Liaoning, are expected to experience initial frost, while southern regions will see a temperature drop of 2°C to 4°C after previously being 5°C to 8°C above normal [2] Warnings and Precautions - Beijing's meteorological authorities have issued blue alerts for cold waves and strong winds, predicting a temperature drop of around 8°C and wind gusts reaching up to 7 levels in certain districts [2] - Frost warnings have been issued for specific districts, indicating potential impacts on agriculture due to low temperatures [2] Health Advisory - The Beijing Center for Disease Control advises the public to take precautions against the cold, including wearing appropriate clothing and protecting vulnerable body parts [3] - Emphasis is placed on the importance of flu vaccinations and maintaining good hygiene practices during the autumn and winter seasons, which are high-risk periods for respiratory diseases [3]