Weather Forecast for Monday, 14 September 2026: Heavy Rain Potential in Sumatra

The Meteorology, Climatology, and Geophysics Agency (BMKG) has released the weather forecast for Monday, 14 September 2026.

Current monitoring of atmospheric dynamics confirms an increase in surface wind speeds across most Indonesian waters, which has the potential to trigger high waves. Alongside this, there is a potential for moderate to heavy rainfall in the western regions of Sumatra and the Riau Islands.

Based on the latest BMKG weather monitoring, Tropical Cyclone Seed 98W was observed centred over mainland Cambodia; however, there is a low probability of it developing into a tropical cyclone, and it is confirmed not to have a significant impact on weather conditions in Indonesia.

Simultaneously, cyclonic circulation has been detected forming in the Pacific Ocean, east of the Philippines. Although this increases the potential for rain in surrounding areas, this circulation will not have a direct or significant impact on the Indonesian archipelago’s weather.

However, BMKG noted a widespread increase in surface wind speeds in the southern waters of Indonesia, including the Java Sea, Flores Sea, Banda Sea, Eastern Sea, Sawu Sea, Arafura Sea, Sulawesi Sea, Maluku Sea, Halmahera Sea, and the waters north of Papua. This increase in wind speed has the potential to boost sea wave heights in these maritime areas.

BMKG advises the public to increase preparedness in facing the potential for moderate to heavy rain, which places Aceh, North Sumatra, and the Riau Islands in the early warning zone.

In addition to the potential for rain, the public and stakeholders in the shipping and maritime sectors are advised to be wary of rising sea waves due to the increase in surface winds.

Residents in the regions of Sumatra, Kalimantan, and Papua (such as Palangkaraya, Tanjung Selor, Pontianak, Banjarmasin, and Manokwari) are also advised to anticipate limited visibility due to the emergence of haze or fog phenomena.