Temperature
Seasonal Temperature Outlook: October-December 2025 (OND)
Issued: 30 Sep 2025
For OND 2025, above-normal temperature is predicted over most of the Maritime Continent and northwestern Mainland Southeast Asia.
For OND 2025, above-normal temperature is predicted over most of the Maritime Continent while a mix of below- to above-normal temperature is predicted over Mainland Southeast Asia (Figure 1). Over northwestern Mailand Southeast Asia and most of the Maritime Continent, most models (more than six models) predict above-normal temperature as the most likely tercile. Over parts of central and eastern Mainland Southeast Asia and the southwestern Maritime Continent, either no dominant, below-normal or near-normal temperature is predicted. There is less agreement between models for these regions, with only some models (4 – 6) predicting near-normal or below-normal temperature. Model skill for predicting above-normal temperature is good for most of Southeast Asia.
Figure 1: Temperature tercile summary predictions of the multi model ensemble for OND 2025 (contains modified Copernicus C3S information).
Figure 2: Number of models in agreement in the multi-model ensemble for the dominant tercile for SON 2025. Where there is no dominant tercile, it refers to the number of models with near-normal tercile (contains modified Copernicus C3S information).
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.