Why does it always rain in autumn?

Because the subtropical high, which should have weakened and retreated southward in autumn, is extremely strong and entrenched in the south of the Yangtze River, resulting in the convergence of cold air and warm air mass in the south to form a stable frontal rain belt, so it rains continuously.

Rain is water drops falling from the clouds. Water on land and sea surface evaporates into steam. Steam rises to a certain height and turns into water droplets when it is cold. These small water droplets form clouds. They collide with each other in the cloud and merge into large water droplets. When it is too big for the air, it will fall from the clouds and form rain.

Extended data:

Entering autumn means that rainfall and storms tend to decrease or decrease, and everything in nature begins to mature from lush. The beginning of autumn does not mean the end of hot weather. As the saying goes, "the summer heat is in dog days", according to the calculation method of "dog days", beginning of autumn is often in dog days until the summer heat, so the weather is still very hot in early autumn, and it will generally get cold after the Millennium solar terms.

The watershed of summer heat is in autumn, not at the turn of summer and autumn. The climate in autumn is divided into two stages, the early autumn is sultry, and the climate tends to be dry and cool after the Mid-Autumn Festival. Generally speaking, in autumn, the height angle of the sun gradually decreases, and the temperature gradually decreases from heat; The autumn wind is cool, the summer heat is gone, the fruits are covered with branches, and the fields are golden.