Subseasonal Weather Outlook and Review

Wetter conditions are predicted over much of western and northern Mainland Southeast Asia in Week 1 (8 – 14 June).

Drier conditions are predicted over the southern Maritime Continent during the next fortnight (8 – 21 June). Drier conditions are also predicted over much of the central and eastern equatorial region in Week 2 (15 – 21 June).

Warmer than usual temperatures are predicted over the western Maritime Continent in Week 1 (8 – 14 June). Warmer than usual temperatures are also predicted over eastern Mainland Southeast Asia and parts of the northeastern Maritime Continent during the next fortnight (8 – 21 June).

A Madden-Julian Oscillation (MJO) signal was present over the Western Pacific (Phase 7) at the start of June 2026, based on the RMM Index. Most models predict the MJO signal to propagate to the Western Hemisphere and Africa (Phase 8) and weaken, becoming indiscernible either by the start of the forecast period or in Week 1 (8 – 14 June). No significant MJO activity is predicted for Week 2 (15 – 21 June).

The outlook is assessed for the region in general, where conditions are relative to the average conditions for the corresponding time of year. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted.

Wetter conditions are predicted over much of western and northern Mainland Southeast Asia in Week 1 (8 – 14 June).

Drier conditions are predicted over the southern Maritime Continent during the next fortnight (8 – 21 June). Drier conditions are also predicted over much of the central and eastern equatorial region in Week 2 (15 – 21 June).

Warmer than usual temperatures are predicted over the western Maritime Continent in Week 1 (8 – 14 June). Warmer than usual temperatures are also predicted over eastern Mainland Southeast Asia and parts of the northeastern Maritime Continent during the next fortnight (8 – 21 June).

A Madden-Julian Oscillation (MJO) signal was present over the Western Pacific (Phase 7) at the start of June 2026, based on the RMM Index. Most models predict the MJO signal to propagate to the Western Hemisphere and Africa (Phase 8) and weaken, becoming indiscernible either by the start of the forecast period or in Week 1 (8 – 14 June). No significant MJO activity is predicted for Week 2 (15 – 21 June).

The outlook is assessed for the region in general, where conditions are relative to the average conditions for the corresponding time of year. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted.