In late November 2025, extreme rainfall struck parts of Southeast Asia, triggering floods, landslides, and claiming many lives.
According to the ASEAN Coordinating Centre for Humanitarian Assistance on Disaster Management (AHA Centre), this disaster was influenced by a weather phenomenon called Tropical Cyclone Senyar.
"The combined impact of the Northeast Monsoon and Tropical Cyclone Senyar has resulted in significant rainfall, triggering widespread floods and landslides in northern Sumatra, Peninsular Malaysia, and southern Thailand," said the AHA Centre in its Flash Update edition November 30, 2025.
Similar statements were made by the Indonesia's Meteorology, Climatology, and Geophysics Agency (BMKG).
"Tropical Cyclone Senyar, which formed in the Strait of Malacca, has significantly influenced the increased intensity of rainfall in the surrounding areas, including Aceh, North Sumatra, and West Sumatra," BMKG stated in a press release on November 27, 2025.
Based on data compiled by the AHA Centre, as of November 30, 2025, the floods and landslides triggered by Tropical Cyclone Senyar have resulted in 168 fatalities in Thailand and 2 in Malaysia.
Meanwhile, in Indonesia, according to data from the National Disaster Management Agency (BNPB), the number of fatalities from similar disasters recorded as of December 4, 2025, at 1:00 PM Western Indonesian Time (WIB) reached 776 people.
Cumulatively, disasters related to Tropical Cyclone Senyar have caused nearly 1,000 fatalities in Southeast Asia, with the highest number of casualties in Indonesia, as shown in the graph.
The number of fatalities may also still increase, as hundreds of people remain missing in Sumatra.
According to BMKG, the intensity of Tropical Cyclone Senyar has now begun to weaken. However, during the period of December 2-8, 2025, there is still a potential for extreme weather in various regions of Indonesia.
"Weather in Indonesia is generally dominated by light to extreme rainfall conditions," BMKG stated in a press release on December 1, 2025.
"There is a need to be vigilant for an increase in moderate intensity rainfall occurring in West Sumatra, Riau, Riau Islands, Jambi, Bengkulu, Lampung, Special Region of Yogyakarta, East Java, Bali, North Kalimantan, South Kalimantan, Gorontalo, Central Sulawesi, South Sulawesi, Southeast Sulawesi, Southwest Papua, West Papua, Central Papua, and Papua," it added.