Rainfall

For JFM 2026, an increase in chance of below-to near-normal rainfall is predicted for much of the equatorial region, with an increase of above-normal rainfall elsewhere in the Maritime Continent, based on the multi-model ensemble (Figure 1). For above-normal rainfall, most models agree for the northeastern part and southern-most part of the region (more than six models) with some models in agreement elsewhere (4 – 6 models, Figure 2). For below-normal rainfall, most models (more than six models) agree for the central equatorial region with little agreement for much of the rest of the equatorial region (less than 4 models).   

For Mainland Southeast Asia, an increase in chance of above-normal rainfall is predicted over the southern portion and below-normal rainfall over the northwestern portion, with no dominant tercile elsewhere. Most models (more than 6 models) agree on the region for below-normal, with some models agreeing (4 – 6) for southern Mainland Southeast Asia. Elsewhere in Mainland Southeast Asia no dominant tercile is predicted.  

Model skill is good over the northern half of the Maritime Continent for predicting above-normal rainfall, and low to moderate for the southern Maritime Continent. Model skill is low to moderate for below-normal rainfall over northwestern Mainland Southeast Asia and the equatorial region.