Rainfall
Seasonal Rainfall Outlook: April-June 2026 (AMJ)
For AMJ 2026, below-normal rainfall for the southern ASEAN region.
For AMJ 2026, an increased chance of below-normal rainfall is predicted for the southern ASEAN region, , based on the multi-model ensemble (Figure 1). Most models (more than six models) agree for the region of higher confidence in below-normal rainfall, with some models (4 – 6 models) predicting below-normal rainfall for the rest of the region. Model skill is low to moderate over the southern ASEAN region at this time of year.
For the northern ASEAN region, no dominant tercile is predicted for much of the region, apart from some models (4 – 6 models) in agreement regarding an increase in chance of above-normal rainfall predicted over much of the northeastern part. Model skill is good over the northeastern region for predicting above-normal rainfall, and low for the rest of the region.
Figure 1: Rainfall tercile summary predictions of the multi model ensemble for AMJ 2026 (contains modified Copernicus C3S information).
Figure 2: Number of models in agreement in the multi-model ensemble for the dominant tercile for AMJ 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 AMJ based on CHIRPS (Reference period: 1991-2020).
Figure 4: Average climatological rainfall's upper tercile boundary for AMJ 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.