Rainfall

Monthly Rainfall Outlook: June 2025

Issued: 23 May 2025

For June 2025, an increased chance of above-normal rainfall is predicted for the southern Maritime Continent. 

For June 2025, above-normal rainfall is predicted for the southern Maritime Continent based on the multi-model ensemble (Figure 1). The highest probability of above-normal rainfall is over the southeastern Maritime Continent (more than 50% chance), with most models (at least six) predicting above-normal rainfall as the dominant tercile for this region (Figure 2). Model skill is moderate to good for the southern Maritime Continent.  

For most of the rest of the Maritime Continent as well as Mainland Southeast Asia, there is little to no agreement on the dominant tercile (less than four models in agreement, Figure 2). Model skill is moderate for the Maritime Continent outside of the southern region, and low to moderate for Mainland Southeast Asia. 

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Figure 1: Rainfall tercile summary predictions of the multi model ensemble for June 2025 (contains modified Copernicus C3S information).
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Figure 2: Number of models in agreement in the multi-model ensemble for the dominant tercile for June 2025. Where there no dominant tercile, it refers to the number of models with near-normal tercile (contains modified Copernicus C3S information).

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Figure 5: Average climatological rainfall's lower tercile boundary for June based on CHIRPS (Reference period: 1991-2020).

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Figure 6: Average climatological rainfall's upper tercile boundary for June 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.