Rainfall
Seasonal Rainfall Outlook: December 2025 - February 2026 (DJF)
Issued: 28 Nov 2025
For DJF 2025-2026, models predict above-normal rainfall over much of the northeastern Maritime Continent.
For DJF 2025-2026, above-normal rainfall is predicted for the northeastern Maritime Continent, with below-normal predicted over parts of the central Maritime Continent and no dominant tercile generally elsewhere, based on the multi-model ensemble (Figure 1). Most models agree on above-normal rainfall as the most likely tercile for the northeastern parts of the region (more than six models, Figure 2). For below-normal rainfall predicted in the Maritime Continent, most models (more than six models) agree with each other for central Borneo with at least some models (4 – 6) elsewhere.
For Mainland Southeast Asia, above-normal rainfall is predicted over the eastern regions with no dominant tercile elsewhere. Most models (more than 6 models) agree on the above-normal rainfall over the eastern portion.
Model skill is good over the northeastern Maritime Continent and eastern Mainland Southeast Asia for predicting above-normal rainfall. Model skill is poor to moderate elsewhere in the region.
Figure 1: Rainfall tercile summary predictions of the multi model ensemble for DJF 2025-2026 (contains modified Copernicus C3S information).
Figure 2: Number of models in agreement in the multi-model ensemble for the dominant tercile for DJF 2025-2026. Where there is no dominant tercile, it refers to the number of models with near-normal tercile (contains modified Copernicus C3S information).
Figure 3: Average climatological rainfall's lower tercile boundary for DJF based on CHIRPS (Reference period: 1991-2020).
Figure 4: Average climatological rainfall's upper tercile boundary for DJF based on CHIRPS (Reference period: 1991-2020).
The qualitative outlook is assessed for the region in general. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted.