Several Indonesian Regions Likely to Experience Rain on 18 March 2026
Indonesia’s Meteorological, Climatological, and Geophysical Agency (BMKG) has forecast weather conditions across several Indonesian regions on Wednesday, 18 March 2026, to be influenced by fairly active atmospheric dynamics. One of the key factors is the formation of cyclonic circulation in several Indonesian waters.
Cyclonic circulation is expected to emerge in the Indian Ocean southwest of Banten, the Timor Sea, and the southern Arafura Sea near South Papua. This phenomenon triggers the formation of convergence and confluence zones—areas where air masses meet—which can enhance the development of rain clouds.
These conditions have been observed in several ocean and land areas, including the Indian Ocean southwest of Banten, the Timor Sea, East Nusa Tenggara, and the Arafura Sea around South Papua. Additionally, convergence zones are also forecast to form across various Indonesian land regions, ranging from Aceh, North Sumatra, Riau, West Sumatra, to Lampung.
Other regions likely to experience similar conditions include East Java, West Nusa Tenggara, East Nusa Tenggara, Kalimantan, Sulawesi, Maluku, and several provinces in Papua.
BMKG has urged the public to heighten vigilance against the potential for heavy to very heavy rainfall in several regions. Areas expected to experience such conditions include the Bangka Belitung Islands, East Java, East Nusa Tenggara, Central Kalimantan, North Sulawesi, West Sulawesi, and Pegunungan Papua.
Additionally, moderate to heavy rainfall is forecast across several other Indonesian regions. This is related to confluence activity along the west coast of Sumatra, the Java Sea, and parts of Kalimantan, Sulawesi, and Papua.
Such atmospheric phenomena commonly occur when air masses from various directions converge and drive the formation of more intense rain clouds.
For western Indonesia, BMKG forecasts the potential for thunderstorms in Banjarmasin and Tanjung Selor. Meanwhile, moderate rainfall is expected in Semarang. Light rain is also likely in much of Sumatra, Serang, Bandung, Surabaya, Pontianak, Palangkaraya, and Samarinda, whilst Jakarta and Yogyakarta are forecast to experience thick cloud cover.
In eastern Indonesia, thunderstorms are predicted in Manado, Kendari, and Nabire. Moderate rainfall is forecast for Merauke, whilst light rain is likely in Denpasar, Mataram, Kupang, most of Sulawesi, Ternate, Ambon, and most of Papua.
BMKG urges the public to continue monitoring weather updates and to heighten vigilance, particularly for regions likely to experience high-intensity rainfall.