Anak Krakatau 2026 Eruption

The story so far

As of September 6, 2026

Anak Krakatau began erupting late on Friday and by Sunday its ash was over the capital’s airspace, forcing Indonesia to suspend operations at eight airports. Jakarta’s Soekarno-Hatta, more than 150 km from the volcano, halted flights before dawn, planned to reopen at 9:30 am, then extended the stop to 1:30 pm and made further extensions through the day. Across the eight airports, 1,558 flights were delayed or canceled and about 170,000 passengers were stranded, with more than 900 affected flights tied to Soekarno-Hatta alone.

The factor driving these decisions is ash at flight altitudes over densely used routes, not activity on the runway. Indonesia’s meteorological agency identified ash up to 6,000 m on the Java side and as high as 15,000 m on the Sumatra side. Fine ash can sandblast windscreens and melt onto hot engine parts, so airspace closures reached well beyond the volcano. Authorities kept ships at least 3 km from the cone, advised residents to stay indoors and wear masks, and prepared cloud seeding to bring rain that could wash ash from the air.

The story has shifted from a local eruption to a regional transport disruption centered on Southeast Asia’s second-busiest airport. Airlines are juggling aircraft and crews as schedules ripple; Singapore Airlines canceled 19 Jakarta flights on Sunday and Scoot canceled 12, while other carriers scrubbed early departures and looked to alternate airports such as Semarang and Surabaya. The binding constraint is when ash clears from the corridors aircraft use, which determines not just when Jakarta can accept flights again but how quickly networks across Indonesia, Singapore, and beyond can be put back in sequence.

Public safety measures are targeted at ashfall and near-crater hazards. The disaster agency kept a 3 km exclusion zone around Anak Krakatau and said there was no imminent tsunami risk, a key point given the deadly 2018 wave triggered by a flank collapse. Schools in Jakarta moved classes online for Monday, and fishing trips were called off in affected coastal areas. What matters now is the direction and height of the ash in the next weather cycles; those readings will dictate how long closures persist and how wide the knock-on effects spread.