Group 1 - The first cold air mass of December is expected to bring significant temperature drops and light precipitation to Hangzhou, with average daily temperature decreasing by 5℃ to 7℃ [2] - The lowest temperatures are forecasted to occur on Thursday and Friday mornings, with plains expected to see temperatures between 1℃ and 4℃, and mountainous areas between 0℃ and 3℃, potentially leading to frost or ice [2] - November was notably dry, with Hangzhou's average temperature at 13.9℃, 0.6℃ above the historical average, and total precipitation at only 28.5mm, about 62% less than normal [1] Group 2 - The incoming cold air mass will also bring some moisture, resulting in light rain in parts of the city from Tuesday afternoon to Wednesday morning, which will help alleviate dryness [2] - The cold air mass is associated with the influx of external pollutants, leading to light pollution levels in Hangzhou and surrounding areas, with air quality expected to deteriorate as the cold front arrives [2] - Residents are advised to take precautions against potential health impacts from air pollution, including wearing masks and minimizing outdoor activities [2]

Core Viewpoint - The recent high-temperature heatwave in Suzhou has shown signs of abating with the arrival of rain, marking a notable weather pattern shift as the city prepares to enter the White Dew solar term on September 7 [1] Summary by Relevant Sections - **High-Temperature Duration and Records** - Suzhou experienced a continuous high-temperature heatwave lasting 17 days as of August 31, which is relatively rare for this time of year [1] - The city recorded 37 high-temperature days this year, with 21 occurring in August alone [1] - The highest temperature reached 39.2°C on August 24, marking a new high for the summer season, while the average temperature that day was 31.4°C, also a historical high for late August in Suzhou [1] - **Weather Forecast and Temperature Trends** - The forecast indicates significant rainfall expected on September 1-2 and September 7, with scattered thunderstorms in other periods [1] - Due to the rainfall, temperatures are expected to decrease initially, but will rise again mid to late week, with maximum temperatures around 35°C projected for September 5-6 [1] - It is anticipated that Suzhou's rainfall in early September will be above the historical average, and temperature fluctuations will occur, with average temperatures in early September expected to be higher than usual [1]