The researchers studied the relationship between the onset of the South China Sea summer monsoon and sea surface temperatures in the Southern Ocean. They found that the monsoon onset date varied significantly from 1979 to 2009. The onset date is linked to sea surface temperatures in the Indian Ocean-Southern Ocean and Pacific-Southern Ocean in the preceding winter and spring. When these temperatures are lower than usual, the monsoon arrives earlier. The Southern Ocean temperatures can predict the monsoon onset, affecting it through air-sea interaction and atmospheric patterns. A strong Antarctic Oscillation during a cold Southern Ocean winter can lead to an early monsoon onset. This study shows how distant ocean temperatures can influence the timing of the South China Sea summer monsoon.