The Twenty-fifth session of the ASEAN Climate Outlook Forum (ASEANCOF-25) was organised by the Ministry of Water Resources and Meteorology, Cambodia (MOWRAM), RIMES, ASMC, the ASEANCOF Working Group, UN ESCAP, and WMO. Participants from the NMHSs of ASEAN Member States created a consensus forecast for the boreal winter monsoon 2025/2026 in the ASEAN region. The consensus for the December-January-February 2025/2026 outlook was achieved through an online session, which included presentations from different NMHSs, questionnaires, and discussions regarding the current climate conditions and predictions for Southeast Asia.