Several Indonesian Volcanoes Erupt at the Same Time: Here Is the List

Volcanic activity increased at several Indonesian volcanoes from August through early September 2026. The Center for Volcanology and Geological Hazard Mitigation recorded five volcanoes at Level III, or Alert, and 22 at Level II, or Watch. Another 42 remained at Level I, or Normal, and none reached Level IV, or Awas.

The five volcanoes at Level III were Anak Krakatau, Semeru, Merapi, Lewotobi Laki-laki and Sinabung. The Level II list included Awu, Banda Api, Bromo, Bur Ni Telong, Dempo, Dieng, Dukono, Gamalama, Ibu, Ile Werung, Ili Lewotolok, Iya, Karangetang, Kerinci, Lokon, Marapi, Raung, Rinjani, Sangeangapi, Slamet, Soputan and Talang. The agency said volcanic status can change after further evaluations.

The most notable change came at Mount Sinabung in Karo regency, North Sumatra. Geological authorities raised its status from Level II to Level III on Aug. 31 at 12:30 p.m., after an eruption sent an ash column about 3,500 meters above the summit, or roughly 5,960 meters above sea level.

The eruption began at about 10:17 a.m. The thick, black ash column moved east to southeast, while a seismogram recorded a maximum amplitude of 120 millimeters during an initial period lasting more than an hour. The National Disaster Management Agency said the eruption directly affected residents.

By Sept. 1, about 211 families, or 615 people, from Kuta Tengah village had moved to an emergency response post in Sukatepu village. Some 405 people were staying at the Jambur Arih Ersada evacuation center in Sukatepu. Local authorities directed residents away from danger zones and distributed masks to people affected by volcanic ash. Geological authorities called the Aug. 31 eruption an initial eruption and said further activity could not be ruled out. Residents may not enter relocated villages, areas within three kilometers of the summit, or certain sectors extending up to six kilometers south-southeast.