Interdecadal Increase of the Contribution of Extreme Precipitation in June in South China

Abstract Extreme precipitation plays an increasingly important role in shaping hydroclimatic risk under global warming, yet its long‐term contribution to total precipitation remains poorly understood. This study investigates the interdecadal changes in the Proportion of Extreme Precipitation to Total Precipitation (PEPTP) in South China from 1961 to 2024. Results show a significant increase in PEPTP since the early 1990s. The Indian Ocean capacitor effect dominate the earlier period, the post‐1992 phase is increasingly influenced by North Atlantic Zonal Dipole (NAZD). Notably, the Pacific Decadal Oscillation (PDO) modulates the NAZD–PEPTP relationship, with a significant positive correlation emerging during negative PDO phases. The recent enhancement of PEPTP coincides with a persistent negative PDO phase. These findings highlight the importance of multi‐oceanic modes and decadal variability in shaping extreme precipitation under climate change.