The Anak Krakatau volcano erupted in Indonesia's Sunda Strait on Sunday, September 6, 2026, leading to the closure of six airports and the cancellation of hundreds of flights. Volcanic ash drifted across parts of the capital city, Jakarta, and southern Sumatra, prompting authorities to warn residents to stay clear of the active crater and wear protective gear against falling ash.
Anak Krakatau, located between the islands of Java and Sumatra, had shown signs of activity since Friday, September 4. The Geological Agency reported that a 30-second eruption occurred at 3:53 a.m. on Sunday. This follows an intensification of activity since July, though officials stated they cannot predict if a larger eruption will follow. A separate eruption was also reported on Sunday at Mount Semeru in East Java, approximately 850 kilometers away.
AirNav Indonesia closed the airspace around Soekarno-Hatta and Halim Perdanakusuma airports in Jakarta, Radin Inten II in Lampung, and three others. By mid-afternoon Sunday, at least 516 flight movements were affected, including 301 at Soekarno-Hatta alone. Major carriers, including Singapore Airlines, Malaysia Airlines, and Batik Air, canceled or delayed flights. Ministry of Transportation Director General Lukman F. Laisa stated that "safety remains our top priority" and warned of cascading disruptions to aircraft rotations and terminal capacity.
The scale of the disruption is significant for Indonesia’s transport network. With ash clouds reaching altitudes between 20,000 and 50,000 feet, the impact extends across several provinces, including Jakarta, Banten, West Java, and Bengkulu. The eruption has cost airlines and airport operators through grounded fleets and the provision of food and hotel accommodations for stranded passengers. The National Disaster Mitigation Agency (BNPB) announced plans for weather modification, including cloud-seeding, to trigger rain in hopes of washing the ash from the atmosphere. This follows a precedent of high volcanic activity in the region; Indonesia currently has five volcanoes at Alert Level 3.
The immediate situation remains fluid as authorities monitor magma levels and gas concentrations. While officials stated there is no imminent risk of a tsunami—recalling the 2018 event that killed 430 people—a 3-kilometer exclusion zone remains around the Anak Krakatau crater. Travelers are advised to monitor flight schedules as airlines work to restore operations, while maritime vessels in the Sunda Strait have been told to remain vigilant. Further updates from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) are expected as they evaluate whether the eruption indicates a larger forthcoming event.