INDOPOSCO.ID – The Meteorology, Climatology and Geophysics Agency (BMKG) has urged the public to remain alert for heavy to extreme rainfall expected to affect most parts of Indonesia on Friday (Jan. 23, 2026).
BMKG forecaster Alya Sausan, speaking on the agency’s YouTube channel monitored in Jakarta on Friday, said heavy to extreme rain could hit Banten and Jakarta.
Meanwhile, heavy to very heavy rainfall is forecast for Lampung, West Java, Central Java, Yogyakarta, East Java, Bali, West Nusa Tenggara (NTB), and East Nusa Tenggara (NTT).
For major cities, weather conditions across Sumatra are expected to vary, with Banda Aceh forecast to be partly cloudy, Tanjung Pinang cloudy, while Medan, Pekanbaru, Jambi, and Pangkalpinang are expected to experience thick cloud cover.
“Padang may experience haze or fog, while Bengkulu and Palembang are expected to see light rain,” Alya said.
Residents of Bandar Lampung are advised to remain alert for rain that may be accompanied by lightning.
On Java Island, moderate rain is forecast for Jakarta, Bandung, Semarang, and Surabaya, while Serang and Yogyakarta may experience thunderstorms.
In Kalimantan, Pontianak and Palangka Raya are expected to be cloudy, while Samarinda and Banjarmasin will see thick cloud cover.
“Light rain is forecast for Tanjung Selor,” she added.
Moving to Bali and Nusa Tenggara, light rain is expected in Denpasar and Kupang, while Mataram is forecast to experience moderate rainfall.
Across Sulawesi, Manado is expected to be cloudy, Kendari and Gorontalo overcast, while Mamuju may see light rain.
“Makassar may experience hazy conditions, while Palu is forecast to see smoke or fog,” she said.
In eastern Indonesia, Ternate is expected to be overcast, while Ambon may experience light rain.
In Papua, Jayapura is forecast to be cloudy, while Sorong will see thick cloud cover. Light rain is expected in Manokwari and Jayawijaya, while Nabire and Merauke may experience moderate rainfall.
BMKG also reported the presence of Tropical Cyclone Seed 91S, detected over the southern Indian Ocean south of Sumbawa, which has a high potential to develop into a tropical cyclone within the next 48–72 hours.
The system is expected to increase wind speeds to more than 25 knots across the southern Indian Ocean off East Java to Sumba Island, as well as Bali, NTB, NTT, and the northern waters from Madura Island to Flores Island. (aro)
