Rising heavy precipitation amid decreasing typhoon contribution in Southeast Asia

Abstract Understanding long-term precipitation changes in Southeast Asia (SEA) is important because the region is highly vulnerable to precipitation-related disasters. This study examines typhoon and non-typhoon heavy precipitation over SEA during 1960–2024 using a typhoon track dataset and three high-resolution precipitation products. Results show a significant decrease in typhoon-precipitation contribution to total precipitation across the entire SEA, both in its continental and maritime regions, especially during the boreal summer half-year. This trend persists under heavy precipitation conditions (95th and 99th percentiles). In contrast, based on tracking results, non-typhoon heavy precipitation shows increases in precipitation area but decreases in lifespan intensity, yielding more total precipitation per event. Our findings indicate a shifting hazard regime: a decrease in typhoon-related rainfall is being offset by a spatial expansion of non-typhoon heavy precipitation, introducing a new regional risk. The findings provide critical insights into the change of regional precipitation patterns and have implications for disaster management and adaptation in SEA.