Mount Anak Krakatau erupted in a continuous episode lasting about 25 hours from late 4 September to early 6 September 2026, triggering massive air travel disruptions across Indonesia on Monday, 7 September 2026. Initial reports indicated that 1,558 flights were delayed or cancelled, affecting approximately 170,000 passengers, but figures rose to more than 2,300 flight disruptions impacting over 270,000 travelers as disruptions continued through the day.
Volcanic Ash Forces Closure of Eight Airports
Eight Indonesian airports were temporarily closed on the morning of 7 September 2026 as a precaution due to volcanic ash dispersal in the airspace over parts of Java, Sumatra, and the Jakarta region. Indonesia’s
Meteorology, Climatology and Geophysical Agency (BMKG) reported volcanic ash spread affecting Banten, West Java, Jakarta, and sections of Sumatra, with ash plumes reaching heights up to 50,000 feet near Sumatra’s side of the Sunda Strait.
Soekarno-Hatta International Airport Most Severely Impacted
The eight airport closures included Soekarno-Hatta International Airport, Indonesia’s main international gateway serving Jakarta, which accounted for more than 900 of the affected flights. Indonesian transport authorities initially stated 1,558 flights were disrupted across the eight airports, with later updates from Reuters increasing the total to above 2,300 flights and 270,000 passengers impacted. Thousands of travelers have been stranded or delayed due to cancellations and
rerouted flights.
Authorities Monitor Ash Movement and Extend Closures
Indonesia’s transport authorities are continuously monitoring ash concentrations and modifying airport closures dynamically rather than setting fixed reopening times. BMKG provides aviation warnings around the clock, tracking ash plume movements which are influenced by wind and weather conditions, complicating efforts to predict affected airspace. Airports operating normally in the morning could face sudden restrictions if ash moves into their flight corridors later in the day.
Geological Context and Ongoing Risk
Mount Anak Krakatau sits in the Sunda Strait between Java and Sumatra, approximately 150 kilometers from Jakarta’s main airport. The volcano has been at alert Level III (Siaga) since 2 July 2026, reflecting
heightened activity and eruption potential. The 25-hour eruptive phase that ended early 6 September was confirmed by Indonesia’s Geological Agency. Authorities maintain an exclusion zone around the volcano due to risks from volcanic debris, and further eruptions remain possible, posing continuing threats to air travel safety.
Flight Disruptions and Passenger Impact
Flight schedules throughout Indonesia, especially those connected to Jakarta, remain highly volatile on 7 September 2026 due to ash presence. The disruption has already affected more than 270,000 passengers, with thousands more likely impacted as airport statuses evolve. Travelers at affected airports are subject to lengthy delays and cancellations. Indonesian authorities have emphasized continuous
monitoring and readiness to extend closures as necessary to ensure aviation safety amid the ongoing volcanic activity.
