Anak Krakatau ash disrupts Indonesian aviation, affecting about 170,000 passengers

Air travel across western Indonesia remained heavily disrupted on September 7, 2026 after ash from Anak Krakatau spread into airspace around Jakarta. As of early September 7, Indonesian authorities had extended temporary closures at eight airports, including Soekarno-Hatta International Airport, the country’s main international gateway.

Indonesia’s transport ministry said the closures were extended until around 9 a.m. western Indonesian time on September 7, with the NOTAM for Soekarno-Hatta running through 8:59 a.m. Halim Perdanakusuma, Radin Inten II, Husein Sastranegara and several other airports across Java and Sumatra were also affected.

The disruption escalated rapidly on September 6. Figures from the transport ministry cited by Reuters showed that more than 1,500 flights across the eight airports were affected, leaving about 170,000 passengers stranded or forced to change their travel plans. Close to 1,000 affected flights were recorded at Soekarno-Hatta alone.

Regional carriers including Singapore Airlines, Malaysia Airlines, AirAsia and Lion Air Group cancelled Jakarta services during September 6. Volcanic ash poses a serious risk to jet engines, cockpit windows and aircraft sensors, which is why airspace can be closed even when surface visibility appears acceptable.

Anak Krakatau lies in the Sunda Strait between Java and Sumatra. Strong eruptive activity began late on September 4 and continued through the weekend. Indonesia’s meteorological agency reported ash reaching roughly 20,000 feet on the Java side and as high as 50,000 feet on the Sumatra side, putting it directly into altitudes used by commercial aircraft.

Authorities have been carrying out repeated ash checks at affected airports and say operations will resume only when safety can be confirmed. Before aircraft return to service, airlines are also expected to inspect engines and external surfaces for ash contamination.

Kertajati, Ahmad Yani and Juanda airports have been prepared as possible diversion points if airlines need alternatives. Because Southeast Asia’s airline network is highly interconnected, a major shutdown in Jakarta can also create knock-on effects for itineraries connecting through Singapore, Kuala Lumpur, Bali and other regional hubs.

Passengers flying to Indonesia or connecting through Jakarta on September 7 should check flight status directly with their airline and airport before leaving for the terminal. Wind direction and ash concentration can change quickly, so a full return to normal operations will depend on real-time safety monitoring.