What weather often appears in South China?

"Returning to Nantian" is the name for the phenomenon of weather resurgence in Hainan, Guangxi and Guangdong in South China. It usually appears in February and March in spring, when the temperature warms up and the air humidity rises sharply.

On a clear night, because there is no cloud, the ground heat dissipates quickly. In the first half of the night, due to the large amount of heat stored on the ground during the day, the temperature is generally not easy to drop below 0℃. Especially in the middle of the night and before dawn, the ground emits a lot of heat, but the heat compensated by atmospheric radiation is very little, and the temperature drops rapidly. When the temperature drops below 0℃, the water vapor in the air near the ground adheres to the clods, stones, leaves, vegetation, low tiles and other objects on the ground and condenses into ice crystal frost.