Rainfall
Monthly Rainfall Outlook: January 2025
Issued: 7 Jan 2025
For January 2025, above-normal rainfall is predicted over parts of the Maritime Continent.
For January 2025, above-normal rainfall is predicted over the northwestern Maritime Continent and parts of the eastern Maritime Continent, based on the multi-model ensemble (Figure 4). The ECMWF model (Figure 2) predicts near- to above-normal rainfall for most of the Maritime Continent, with the UK Met Office model (Figure 3) predicting near- to above-normal rainfall apart from over the equatorial region, where below- to near-normal rainfall is predicted. The NCEP model (Figure 1) predicts above-normal rainfall over northern Borneo and parts of the Philippines, with below- to near-normal rainfall for most of the rest of the Maritime Continent. Model skill is moderate to good for the parts of the Maritime Continent north of the equator and low to moderate for the parts to the south, in line with the better agreement between the models for the northern half of the region.
Over Mainland Southeast Asia, there is little agreement between the models (Figures 1 – 3). Model skill for this region is generally low at this time of the year.
Figure 1: Rainfall tercile summary predictions of NCEP model for January 2025 (contains modified Copernicus C3S information).
Figure 2: Rainfall tercile summary predictions of ECMWF model for January 2025 (contains modified Copernicus C3S information).
Figure 3: Rainfall tercile summary predictions of UK Met Office model for January 2025 (contains modified Copernicus C3S information).
Figure 4: Rainfall tercile summary predictions of the multi-model ensemble for January 2025 (contains modified Copernicus C3S information).
Figure 5: Average climatological rainfall's lower tercile boundary for January based on CHIRPS (Reference period: 1991-2020).
Figure 6: Average climatological rainfall's upper tercile boundary for January 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.