2025年北方首场高温过程开启，局地气温或达40℃及以上

Summary of Key Points Core Viewpoint - The northern region of China is experiencing its first heatwave of the year, with temperatures expected to reach or exceed 40°C in several areas from May 19 to 22, while the southern region will continue to face heavy rainfall, raising concerns about secondary disaster risks [1][2]. Group 1: Northern Heatwave - The first heatwave in the northern region is set to impact areas such as Northwest, North China, and Huanghuai, with temperatures potentially reaching 40°C [1][2]. - Key affected areas include Ningxia, Shaanxi, Henan, Shandong, Shanxi, and northern Hubei, where temperatures will exceed 35°C, with some locations experiencing highs of 37 to 40°C [2]. - Shaanxi is identified as the core area for this heatwave, with the longest duration of high temperatures lasting 3 to 4 days, and some places may reach historical temperature extremes [2]. Group 2: Southern Rainfall - The southern region continues to experience a rainy pattern, with heavy rainfall expected in areas such as Jiangnan and South China, including potential localized heavy rain or torrential downpours [3]. - The Central Meteorological Observatory forecasts significant rainfall in regions like southern Zhejiang, southeastern Jiangxi, central and northeastern Guangxi, and western Guangdong, with some areas facing heavy rain [3].