This publication presents findings from a climate change risk and adaptation assessment in southern Viet Nam as part of the Water Efficiency Improvement in Drought-Affected Provinces (WEIDAP) project supported by the Asian Development Bank. It highlights new developments and key lessons on climate risk assessment that may be applied to the project design and monitoring as well as the implementation of climate adaptation measures. The WEIDAP project was developed in response to the drought that affected southern Viet Nam in 2015–2016. It focused on irrigation modernization and the integration of climate-resilient agricultural and efficient on-farm water management practices.