Dou called the southeast dimension the source of long summer.

Sinus refers to the southeast, Wei refers to the long summer. This sentence is from the almanac.

"Almanac": "Dou refers to the southeast, Wei is the long summer, and everything has grown up since then, so it is named long summer." After the long summer, sunshine increased, gradually warmed up, and thunderstorms increased. Long summer is an important solar term, marking the peak season for the growth of all things. In the long summer, everything is thriving.

Long summer is the seventh of the 24 solar terms and the first solar term in summer. Long summer bid farewell to spring, which is the beginning of spring, so it is also called "the end of spring".

After the long summer officially entered the rainy season, rainfall and rainy days increased significantly. Summer is the best season for many crops to grow vigorously. Adequate light, suitable temperature and abundant rain provide necessary conditions for plants. In summer, affected by the warm and humid air flow from the ocean, the southern region is generally hot, humid and rainy. Qinling-Huaihe river basin is a transitional area between rainy south and rainy north. From the vicinity of Huaihe River in Qinling Mountains to the north, the rainfall decreased sharply. In the long summer, everything is thriving.

Because China has a vast territory and a large span from north to south, natural rhythms vary from place to place. Before and after the "long summer", only the area south of Fuzhou-Nanling line in China may enter summer, and most of the rest areas are still in spring, and some areas in Northeast China and Northwest China even just entered spring at this time.