Rainfall
Seasonal Rainfall Outlook: July-September 2025 (JAS)
Issued: 24 Jun 2025
For JAS 2025, above-normal rainfall is predicted for much of the Maritime Continent.
For JAS 2025, above-normal rainfall is predicted for much of the Maritime Continent, based on the multi-model ensemble (Figure 1). The highest probability of above-normal rainfall is over the eastern Maritime Continent. Most models agree on above-normal rainfall as the most likely tercile for much of the southern half of the region (more than six models, Figure 2). Model skill for predicting above-normal rainfall is good for the southern half of the Maritime Continent and low to moderate elsewhere.
For Mainland Southeast Asia, there is little to no agreement on the dominant tercile over most of the region (less than four models in agreement, Figure 2). Model skill is low to moderate for Mainland Southeast Asia.
Figure 1: Rainfall tercile summary predictions of the multi model ensemble for JAS 2025 (contains modified Copernicus C3S information).
Figure 2: Number of models in agreement in the multi-model ensemble for the dominant tercile for JAS 2025. Where there no dominant tercile, it refers to the number of models with near-normal tercile (contains modified Copernicus C3S information).