- Indonesia's Transport Ministry now says more than 270,000 passengers and roughly 2,300 flights have been affected since the Anak Krakatau eruption began disrupting air travel on Sept. 5 — well above the 150,000-passenger figure circulating a day earlier.
- Seven of eight closed airports, including Jakarta's Soekarno-Hatta, stayed shut into Monday evening; an eighth, in South Sumatra, reopened Monday morning.
- Officials say they're basing reopening decisions on repeated negative ash tests, not a fixed timeline, and warn that another eruption remains possible in the coming days.
Volcanic ash from Mount Anak Krakatau has grounded roughly 2,300 flights and left more than 270,000 travelers stranded across Indonesia since the eruption intensified on Sept. 5, according to a Transport Ministry statement issued Monday — a toll far higher than initial weekend estimates suggested.
Seven of the eight airports closed over the weekend remained shut through Monday evening as ash kept drifting over Java and Sumatra, while Indonesian officials warned that another eruption could strike with little notice.
A fast-moving tally: from 150,000 to more than 270,000
The scale of the disruption has grown as Indonesian authorities update their count. Early Sunday, the ministry's tally stood near 150,000 affected passengers and roughly 467 flights; by Monday, cumulative figures published by the ministry and reported by outlets including Malay Mail and Al Jazeera put the total at 2,319 disrupted flights and 270,337 affected passengers — cancellations, delays and diversions combined — since the eruption began disrupting air travel on Sept. 5. Officials described the jump as a running total rather than a sudden worsening on the ground, noting that the number folds together both the airports shut outright and the knock-on effect on flights rerouted elsewhere, according to a ministry breakdown cited by Arabian Business.
Eight airports, one eruption
Ash from Anak Krakatau, sitting in the Sunda Strait roughly 150 kilometers (90 miles) from Jakarta, forced closures at Halim Perdanakusuma and Soekarno-Hatta International in Jakarta; Muhammad Taufiq Kiemas and Radin Inten II in Lampung province; Budiarto and Pondok Cabe near Tangerang; Husein Sastranegara in Bandung; and Atung Bungsu in South Sumatra, per a roster compiled by Asia News Network. Atung Bungsu, the smallest of the group, reopened Monday morning once inspectors cleared it of ash. The other seven, including Soekarno-Hatta, the country's busiest airport, had their closures pushed to 6 p.m. local time (1100 GMT) Monday, said airport operator Angkasa Pura, which runs the hubs under the state-owned InJourney Airports group, in an online statement flagged by the Jakarta Post.
Why officials won't commit to a reopening time
Transport Minister Dudy Purwagandhi told reporters that ash tests at Soekarno-Hatta had come back clean four times running, yet the airport would stay shut anyway until officials felt fully confident conditions had stabilized. Purwagandhi made the comment Monday while updating President Prabowo Subianto, according to a separate Malay Mail report. Shifting winds, he added, raised the odds that ash could blow back over the field even after a clean reading. "We cannot ascertain when this will end due to the dynamic weather," Purwagandhi said of the closures.
What's actually happening inside the volcano
Indonesia's Ministry of Energy and Mineral Resources says the volcano entered a continuous eruption lasting roughly 25 hours starting at 11:07 p.m. local time Friday, throwing lava into the air and producing a boom reportedly audible some 700 kilometers away before tapering off early Sunday, according to a translation reported by CNBC. Wire dispatches from Reuters and the Associated Press have generally dated the eruption to Saturday, when the ash cloud that grounded flights became visible — a gap that appears to reflect where each account starts its clock rather than any dispute over what happened. Indonesia's Geological Agency logged a further eruption Sunday night and cautioned Monday that further activity remained likely in the days ahead, with agency head Lana Saria pointing to risks such as thick ashfall, flying volcanic rock and fresh lava if the activity flares again. Meteorological agency BMKG tracked two separate plumes: one near 20,000 feet drifting toward Jakarta and West Java, the other climbing roughly 50,000 feet over Lampung, Bengkulu and stretches of the Indian Ocean.
Ripple effects beyond the runway
Singapore Airlines, Malaysia Airlines, AirAsia and the Lion Air Group scrapped Jakarta routes over the weekend, while Garuda Indonesia grounded flights and Citilink travelers queued for refunds, based on coverage from CNN and PBS News. International links to Amsterdam, Doha, Hong Kong, Kuala Lumpur, Seoul, Singapore and Sydney were among those disrupted. By Monday some carriers were already rebuilding their schedules — Vietnam Airlines added recovery flights connecting Jakarta with both Hanoi and Ho Chi Minh City — while Indonesian authorities kept six backup airports standing by across East Java, Central Java and Yogyakarta for diverted traffic. Schools in Jakarta, West Java, Banten and Lampung switched to remote learning to limit children's exposure to airborne ash, and national disaster agency BNPB said it was weighing cloud-seeding to trigger rain that might wash the particles out of the sky.
A volcano with a deadly history
Anak Krakatau — its name translates to "Child of Krakatau" — first broke the surface of the Sunda Strait in the 1920s, inside the void left by the devastating 1883 blast that destroyed its parent volcano, among the deadliest on record. A partial collapse of the island in December 2018 triggered a tsunami that killed at least 429 people along the coasts of Java and Sumatra with no warning, a memory that hangs over the current closures even though officials say this eruption poses no comparable tsunami threat. Volcanic ash remains a serious hazard to aircraft regardless: fine particles of pulverized rock can melt inside jet engines, pit windshields and cut visibility, which is why regulators lean toward precautionary grounding rather than risk trouble mid-flight.
For now, Indonesian officials say reopening hinges on repeated clean ash readings rather than a set clock, and they are not ruling out fresh disruption if the volcano flares up again in the coming days.
