Group 1 - The weather in Hangzhou has experienced a significant temperature drop from 39.4°C on September 8 to a maximum of 30.7°C recently, attributed to the influence of cold air and moisture from the southwest [1][2] - Rainfall is expected to be frequent across the province until next Friday (19th), with specific weather patterns indicating systematic rain or thunderstorms from the 16th to 17th [1][2] - The overall high-temperature weather is coming to an end, with the southern regions potentially experiencing isolated high temperatures before a more stable cooler weather pattern sets in [2] Group 2 - Nationwide, rain and cooling trends are dominating the weather scene, with the weakening of the subtropical high pressure contributing to the drop in high temperatures [2] - A new round of strong rainfall is anticipated in northern regions, particularly in Henan and Shandong, which may experience rare heavy rain during this period [2] - The competition between the "autumn tiger" (late summer heat) and cold air is ongoing, with expectations of a noticeable cold air mass moving southward from the 15th to 17th [2]