今晨7省会气温创新低，漠河低温达-18.8℃，较强冷空气将上线，新疆局地大到暴雪

Group 1 - The article highlights a significant drop in temperatures across several provincial capitals in northern and central China, with seven cities recording their lowest temperatures since the beginning of autumn [1] - Specific temperature records include Xining at 2.9°C, Shenyang at 5.3°C, Zhengzhou at 9.6°C, Jinan at 10.8°C, Wuhan at 15°C, Changsha at 16.5°C, and Nanchang at 20.3°C, with Zhengzhou being the first to fall below 10°C after autumn began [1] - The lowest temperature recorded was in Mohe, Heilongjiang, at -18.8°C, marking the lowest temperature reported by national meteorological stations since the start of autumn [1] Group 2 - Heavy rainfall and localized torrential downpours were reported in various regions including southwestern Guizhou, southeastern Chongqing, and parts of Hubei, Zhejiang, Fujian, Jiangxi, and Guangxi, with expectations of continued rain in the coming days [3] - A strong cold front is anticipated to bring significant temperature drops of 4-8°C across many regions, with some areas experiencing drops exceeding 10°C, accompanied by strong winds [3] - The article warns of potential hazards such as mountain floods and landslides due to persistent rainfall, advising the public to stay away from mountainous and valley areas [4]