Anak Krakatau Eruption 2026

Anak Krakatau Eruption: Where It Stands

Anak Krakatau, the volcano in the Sunda Strait between Java and Sumatra, erupted on 5 September 2026 and sent ash over western Java, closing eight airports including Jakarta’s Soekarno-Hatta and disrupting nearly 3,000 flights. The airports reopened on 8 September, and we have found no flight, ferry or tourism restriction since. The volcano is now at alert level III (“Siaga”), the second highest of four, with a 5 km exclusion zone that bars residents and tourists.

It is still erupting in small bursts, with the latest reports we found dated 20 October. A volcanic eruption is force majeure, so airlines owe a refund or rebooking but not fixed compensation. A larger eruption could close Jakarta’s airports again at short notice, so check your flight on the day.

Background: What Happened

Anak Krakatau, “child of Krakatau”, sits on its own small island in the Sunda Strait and grew out of the same underwater caldera as the original Krakatau, whose 1883 eruption was one of the deadliest in recorded history. It first broke the surface in 1927. In December 2018 a flank of the cone collapsed into the sea without warning and set off a tsunami that killed more than 400 people along the Sunda Strait coast; the volcano lost roughly two-thirds of its height. That history is why the coast watches it closely, although no tsunami warning has been reported for the 2026 activity.

The 2026 event began with a run of eruptions that led Indonesia’s Geological Agency (Badan Geologi, whose volcano centre is PVMBG) to lift the volcano to alert level III on 2 July. Activity stepped up from the night of 4 September, and the main eruption on Saturday 5 September closed eight airports. Level IV, which would signal an eruption in progress or imminent with wider evacuation, has never been declared.

Timeline

Eruption starts

• 2 July. The Geological Agency raises Anak Krakatau to level III after a run of eruptions.
• Late Friday 4 September. The sequence begins with near-continuous lava fountaining, the volcano’s strongest run of activity this year (Al Jazeera; Antara Jatim, citing the Ministry of Transport).
• Saturday 5 September. AFP via The Jakarta Post says the volcano “erupted on Saturday”, and Antara says ash began affecting airspace that day. No source we read gives an exact time for the main explosion, so we do not give one. The blast lasted around half a minute and was heard up to 700 km away. Two plumes formed: one rose to roughly 6,000 m and drifted northeast over Jakarta, Banten and West Java, and a taller one, estimated at about 15,000 m by Suara (estimator not named), moved west over Lampung, Bengkulu and the Indian Ocean.
• Sunday 6 September. BMKG recorded two new eruptions (Al Jazeera). The alert level was III with a 3 km exclusion zone, no evacuation had been ordered and no casualties had been reported.

Travel impacted

• Soekarno-Hatta. Ash reached the Jakarta airports in the early hours of Sunday 6 September. The Ministry of Transport closed Soekarno-Hatta from 01:30 WIB under NOTAM A3341/26 (detik; Antara Jatim); a list attributed to BMKG gives 02:08 WIB (IDN Times). Its reopening was pushed back repeatedly, and on 7 September Angkasa Pura extended the closure there and at three other airports to 18:00 WIB (AFP via The Jakarta Post).
• Eight airports. Bernama listed Soekarno-Hatta, Halim Perdanakusuma, Radin Inten II (Lampung), Husein Sastranegara (Bandung), Budiarto, Pondok Cabe, Taufik Kiemas (Pesisir Barat) and Atung Bungsu (Pagar Alam). One Antara report of 8 September names Salakanegara (Tanjung Lesung, Banten) as the eighth instead, while another lists Atung Bungsu. We could not settle this and use Atung Bungsu. The Transport Minister said on the evening of 6 September that all eight would stay closed until midnight.
• Flight counts. These are snapshots of different scope and hour. On 6 September Angkasa Pura counted about 301 affected flights at Soekarno-Hatta; Bernama at least 467 flights and about 150,000 passengers across the eight airports; Antara 764 scheduled flights at Soekarno-Hatta by that evening; Al Jazeera a Transport Ministry figure of 1,558 delayed or cancelled flights and more than 270,000 stranded passengers since 5 September.
• Reopening. Soekarno-Hatta, Halim Perdanakusuma and Husein Sastranegara reopened just after midnight on 8 September (00:01 WIB per Antara, 00:30 WIB per a later Antara report citing AirNav), after about two days shut at Soekarno-Hatta. AFP via The Jakarta Post and Reuters via Al Jazeera put the whole closure at nearly 3,000 flights and more than 340,000 passengers. BMKG declared the eight reopened airports safe from ash.
• Airlines and ashfall. On 6 September Singapore Airlines cancelled its Jakarta services for the day, Batik Air dropped several Kuala Lumpur to Jakarta flights, and a Bali-bound Air India flight turned back to Delhi. Carriers with the most Jakarta departures, among them Indonesia’s flag carrier, moved passengers onto later services after reopening. Ashfall was light: confirmed on the Serang coast and in Bandar Lampung, where schools and fishing were suspended for the day, with only a trace in Jakarta.
• Ferries. ASDP said the Merak to Bakauheni crossing kept running normally on 6 September. On 10 October the Bakauheni port authority said crossings were on schedule in both directions after the alert upgrade, and that Bakauheni, about 45 km from the volcano, is well outside the 5 km zone.

Response

• 6 September. The national disaster agency BNPB urged calm, flew cloud-seeding missions from Pondok Cabe to rain the ash out, and advised residents of ash-affected areas to wear masks and eye protection, limit time outdoors and cover water storage.
• Transport Ministry. It said passengers whose flights were cancelled because of the ash are entitled to a full refund.
• 21 September. After two weeks of fading activity the Geological Agency lowered the volcano to level II (“Waspada”) and cut the exclusion zone from 3 km to 2 km. It told people on the Banten and Lampung coasts to stay calm, ignore rumours of a tsunami and follow the local disaster agency (BPBD).
• 9 October. At 21:00 WIB the agency raised the volcano back to level III and widened the zone from 2 km to 5 km from the eruption centre, with entry also barred within 1 km of the two new islands.
• 11 October. The head of the Lebak disaster agency said tourists, residents, journalists and hikers are not allowed into the volcano area.

Where it stands now

• 2 October. Satellite images showed two small new landforms in the caldera, about 760 m northwest and 495 m southwest of Anak Krakatau. PVMBG head Rita Susilawati told AFP it is too early to say whether they are new vents or debris heaps. Landmasses that appeared here from 1927 washed away before a lasting island formed in 1930.
• 5 to 8 October. Short eruptions: Antara logged four on 5 October and one on 8 October (CNBC Indonesia). Incandescence became visible on 6 October. Sulphur dioxide emissions were roughly 71 to 237.5 tonnes a day between 21 September and 9 October, which the agency described as low.
• 7 October. Radar Banten reported weekend visits to Carita beach at only 30 to 40% of the normal 70 to 90%, citing unattributed data, while a local tourism group head said Pandeglang beaches were safe. We found no newer visitor figures.
• 9 October. The busiest day: Antara logged nine eruptions up to 19:20 WIB, Bernama at least 13, and the observation post later put the day at 26. Ash columns were about 250 m and 150 m, and the Darwin Volcanic Ash Advisory Centre reported ash at about 1.8 km above sea level drifting west, forecast to dissipate within 6 to 12 hours (Bernama).
• 10 to 12 October. No eruptions were recorded, and the observation post said 31 had occurred from 5 to 9 October. No report from 9 to 12 October mentions an airport closure or flight disruption.
• 17 October. An eruption at 01:35 WIB, plume not visually observed. Katadata counted 149 eruptions in 2026 as of that day.
• 18 October. Eruptions at 11:44, 12:01 and 12:59 WIB, the second with ash about 500 m above the summit (Suara), and another at 22:25 WIB that took Katadata’s 2026 count to 159. Observation post head Suwarno repeated level III and the 5 km no-go zone and urged fishermen to follow official updates.
• 20 October. The newest reports we found, and nothing later turned up in searches on 24 October. PVMBG recorded four eruptions, including ones at 06:40 and 12:28 WIB, with no plume visually observed, level III and the 5 km zone unchanged, and 166 eruptions in 2026 so far (Katadata). Counts differ between reports, so treat totals as approximate. None of the 17 to 20 October reports mentions flights or ferries.
• Watching. The agency is tracking eruption counts, incandescence, sulphur dioxide output and the two new landforms.

How This Impacts Travelers

Jakarta flights and the Java to Sumatra ferry are running, so keep your plans but check on the day. A new sustained phase could put ash over Jakarta at short notice.

• Flights. Check your airline’s app before leaving for the airport; it updates first, then the airport’s departures board. Closures usually last hours to about a day, though a drifted plume can swing back and knock-on delays last a day or two. This one ran longer, with Soekarno-Hatta shut for about two days. Ash can melt inside a jet engine, so advisories from the Darwin VAAC lead to hard closures, not delays.
• Ferries. Merak to Bakauheni ran normally through the eruption and on 10 October. ASDP’s contact centre is 191.
• Boat trips to the volcano. The 5 km zone covers tourists, so landing on the island or circling close to the crater is off limits, as is the 1 km around the two new islands.
• Anyer and Carita coast. Well outside the exclusion zone. Early September ashfall was light but real, enough to close schools and call for masks and slower driving.
• Bali and Jakarta. Bali is more than 1,000 km east of the volcano and outside the ash path. No Bali airport is among the eight that closed, all of which are in Java and Sumatra per Bernama. See Bali plans, getting to Bali by air and when to go to Bali. Jakarta itself saw only a trace of ashfall and no evacuation.
• Tsunami risk. No warning has been reported, and the Geological Agency has told coastal residents to ignore rumours of one.
• Your rights. Under Ministerial Regulation PM 89 of 2015, a cancelled flight gets a full refund or a free rebooking to the next available flight, your choice, and long delays bring meals and, overnight, accommodation. Eruptions are force majeure, so fixed delay compensation does not apply. Contact the airline directly rather than queueing at the counter; if you booked through an agent, the refund usually goes back through them.
• Travel insurance. Cover turns on when you bought the policy: once an eruption is in the news it is a known event, so a policy bought after about 5 September will generally not cover it. Some policies name volcanic ash and airspace closure as covered, others exclude ashfall or “acts of nature”. Read the disruption and natural-catastrophe sections and keep every receipt.
• Check live. The Geological Agency’s MAGMA Indonesia portal shows the alert level, the Darwin VAAC shows ash-cloud position, and BNPB posts ashfall, school and port closures.

Anak Krakatau is one of several Indonesian volcanoes that close airports. Which hubs are exposed depends on which volcano is active and which way the wind blows.

Sources for This Anak Krakatau Update

• Four eruptions on 20 October (Katadata, 20 October 2026), with the 06:40 WIB eruption (Katadata, 20 October 2026).
• Eruption at 22:25 WIB on 18 October (Katadata, 18 October 2026, in Indonesian).
• Three eruptions at 11:44 (Suara, 18 October 2026, in Indonesian).
• Eruption at 01:35 WIB on 17 October (Katadata, 17 October 2026).
• Alert raised to level III at 9pm on 9 October (Bernama via Malay Mail, 10 October 2026).
• Geological Agency statement raising the alert to level III (detikNews, 9 October 2026, in Indonesian), and the agency’s reasons, including incandescence since 6 October (IDN Times, 10 October 2026, in Indonesian).
• Nine eruptions on 9 October up to 19:20 WIB (Antara via CNN Indonesia, 10 October 2026, in Indonesian).
• 31 eruptions from 5 to 9 October (Antara via Koran Jakarta, 12 October 2026, in Indonesian), and the Lebak disaster agency barring tourists, residents, journalists and hikers (Antara via Koran Jakarta, 12 October 2026, in Indonesian).
• Bakauheni port authority on normal Merak to Bakauheni crossings after the upgrade (detikSumbagsel, 10 October 2026, in Indonesian).
• The 9 October eruption as reported before the upgrade (Antara, 9 October 2026), and the Geological Agency’s reports of the 5 October eruption and 8 October eruption (CNBC Indonesia, in Indonesian).
• Visitor numbers on the Carita coast (Radar Banten, 7 October 2026, in Indonesian).
• PVMBG on the two new islands (AFP via The Jakarta Post, 2 October 2026).
• Geological Agency statement lowering the alert to level II on 21 September, with the reasons, the then 2 km zone and the tsunami-rumour advice (CNBC Indonesia, 21 September 2026, in Indonesian).
• The volcano “erupted on Saturday” (AFP via The Jakarta Post, 8 September 2026), and the Transport Ministry on the reopening (Reuters via Al Jazeera, 8 September 2026).
• Ash affecting airspace from Saturday 5 September (Antara, 8 September 2026), and BMKG on the eight reopened airports (Antara, 8 September 2026).
• Soekarno-Hatta and three other airports extending their closure on Monday 7 September to 18:00 WIB (AFP via The Jakarta Post, 7 September 2026).
• The list of eight airports with 467 flights and about 150,000 passengers (detikJabar, 7 September 2026, in Indonesian).
• Eruption beginning late on Friday (Al Jazeera, 6 September 2026, updated 7 September).
• 467 flights (Bernama, 6 September 2026).
• 764 scheduled flights affected at Soekarno-Hatta, 185 of them international (Antara, 6 September 2026).
• 301 flights at Soekarno-Hatta (Straits Times via Asia News Network, 6 to 7 September 2026).
• Soekarno-Hatta closed from 01:30 WIB under NOTAM A3341/26 (detik, 6 September 2026, in Indonesian), and the same Ministry statement, with the eruption series since Friday night (Antara Jatim, 6 September 2026, in Indonesian).
• BMKG list of the eight closure windows (IDN Times, 6 September 2026, in Indonesian).
• ASDP statement that the Merak to Bakauheni ferry was running normally (IDX Channel via RCTI+, 6 September 2026, in Indonesian).
• Ash column estimated at about 15 (Suara, 5 September 2026, in Indonesian).