Past hydroclimatic conditions in southern China are poorly constrained owing to the lack of high-resolution marine-sediment records. In this study, we present high-resolution geochemical and grain-size records of marine sediments from the coastal shelf of the northern South China Sea to investigate regional hydrological variations. Results suggest a warm and humid climate during the interval 9 200–7 600 cal a BP, followed by a cold and dry climate from 7 600 cal a BP to 6 500 cal a BP, and progressive humidification during the period 6 500–6 200 cal a BP. A prominent hydrological anomaly occurred during 7 600–6 500 cal a BP. This abrupt event corresponds closely to tropical Pacific and interhemispheric temperature gradients, suggesting that moisture variations in southern China may have been driven by interhemispheric and zonal Pacific temperature gradients via modulation of the intensity and location of the West Pacific subtropical high.