It is generally believed that the Asian summer monsoon first establishes in May over the Arabian Sea, Bay of Bengal, Indochina Peninsula and South China Sea, that is, generally with the latitudes lower than 20° N, and these regions are known as the tropical Asian summer monsoon (TASM) region. This study reveals that the climate in May over Yunnan (Latitude ~25° N), Southwest China, where the rainy season starts also in May, sh...

In this study, the authors identify a decadal decrease in May precipitation over Yunnan, China, after 2009. Based on observed data from meteorological stations, the area‐average precipitation in May over Yunnan has decreased from 135 mm during the period 1999–2008 to 83 mm during the period 2009–2019. The decline in precipitation is particularly pronounced in the southwestern and central regions of Yunnan, where it exceeds 100...