The influence of monsoon is the main reason for the uneven distribution of precipitation in time and space. Under the influence of the summer monsoon, the precipitation in China gradually decreases from the southeast coast to the northwest inland, resulting in the annual precipitation changes in Taipei, Wuhan, Xi and Urumqi as follows: Taipei >; Wuhan >; Xi' an > Urumqi.

Precipitation is a measure of precipitation in a region. Specifically, it refers to the depth at which liquid and solid (after melting) precipitation falls from the sky to the ground without evaporation, infiltration and lossless accumulation on the horizontal plane.

Extended data

The distribution characteristics of precipitation in an area can be divided into two parts: regional distribution and seasonal distribution. China is located in the east of Asia-Europe continent and the west coast of the Pacific Ocean, with great differences in thermal properties between land and sea, forming the most typical monsoon climate in the world. The precipitation in China is mainly brought by the southeast monsoon in summer.

The southeast monsoon brings the water vapor from the Pacific Ocean to China, and the southeast coastal areas of China will be the first to get the water vapor brought by the southeast monsoon, forming rich precipitation and becoming the region with the richest annual precipitation in China.

Judging from the regional distribution of annual precipitation, the annual precipitation in China generally decreases from southeast to northwest, and the northwest region of China has become the region with the least annual precipitation because it is located inland and far from the ocean.

Judging from the seasonal distribution of precipitation, precipitation in China is mainly concentrated in summer, that is, when the southeast monsoon prevails, so the climate characteristic of China is "the same period of rain and heat". The northwest monsoon from Eurasia prevails in winter in China, with less water vapor content and less precipitation.

Besides the precipitation brought by the southeast monsoon, China can also get water vapor from the southwest monsoon of the Indian Ocean. Southwest China is greatly influenced by the southwest monsoon, for example, the southwest monsoon passes through the Yarlung Zangbo River basin.

Send the warm and humid Indian Ocean water vapor to the depths of the Qinghai-Tibet Plateau. In the northern part of northwest China, a small amount of water vapor from Atlantic Ocean and Arctic Ocean can be obtained, which makes the northern part of Xinjiang in China relatively humid compared with the southern part.