Why does it always rain at night?

It is caused by the circulation of the earth's atmosphere. The southeast of our country is the ocean. The earth rotates from west to east, and the water vapor evaporated by the ocean in the air during the day will also drift from west to east with the inertia of the air. When it meets cold air over China, it will turn into rain and fall to the ground. This is also the reason why there are more thunderstorms in the afternoon.

The atmospheric circulation from west to east is also the reason why southeast winds often blow in summer in China. It is often said: "The east wind is sunny all the year round, and I am afraid of the east wind (it will rain)." However, the easterly wind formed by general atmospheric circulation is relatively small. If the east wind blows hard, it must be caused by a tropical cyclone in the ocean. The water vapor in the ocean accelerates over China, and the convection is strong, so rain will come soon, and it is often accompanied by lightning.