Anak Krakatau Eruption 2026

Where Things Stand Now

All eight airports closed by the ash are back to normal operations. Soekarno-Hatta and Halim Perdanakusuma in Jakarta resumed early on 8 September, after four of the airports had held their closures to 6pm on 7 September. AirNav Indonesia kept aircraft routing around the ash cloud rather than through it while the plume was active.

The disruption was much larger than the first day’s numbers suggested. Indonesian authorities put the running total across 5 to 8 September at roughly 2,900 flights and about 341,000 passengers, with more than 270,000 travellers stranded at the weekend peak. Husein Sastranegara in Bandung was among the eight airports shut at various points. Schools across Jakarta, West Java, Banten and Lampung moved to remote learning during the heaviest ashfall.

The Eruption Has Not Ended

The sustained phase that began late on 4 September ran for about 25 hours before easing early on 6 September. Since then Anak Krakatau has settled into weaker, intermittent Strombolian bursts, which continued through 7 and 8 September. The alert level has stayed at III throughout, the second highest of four, and has not been raised to IV.

Indonesia’s Geological Agency has said the probability of further eruptions in the coming days remains high, listing volcanic bombs, heavy ashfall and possible lava flows among the hazards if another sustained phase develops. No tsunami warning has been issued, no evacuation has been ordered, and no casualties have been reported.

If You Are Travelling This Month

Flights through Jakarta are running normally again, but the volcano is still active and a fresh plume could close the airports again at short notice, the way it did on 6 September. If you fly to or from Jakarta, Lampung or Bandung in the next few weeks, check your airline’s app and the airport’s own channels before leaving for the airport, and keep the refund and rebooking rights set out below in mind. Bali, more than 1,000 km east, stays outside the ash path and has not been affected.

The report below describes the situation as it stood on 6 September, the day of the main eruption.

Indonesia’s Anak Krakatau volcano erupted before dawn on 6 September 2026, pushing volcanic ash over western Java and closing Jakarta’s two airports for much of the day. Soekarno-Hatta International, one of Southeast Asia’s busiest hubs, halted all flights, along with Halim Perdanakusuma in Jakarta and Radin Inten II in Lampung. The airport operator put the disruption at about 300 flights, roughly 58 of them international. No casualties were reported and no evacuation was ordered. As of 6 September the alert level sits at III, the second highest of four, with a 3 km exclusion zone around the crater. Light ashfall reached parts of Banten and Lampung; Jakarta itself saw only a trace.

What Happened

Anak Krakatau sits in the Sunda Strait, on its own small island between Java and Sumatra. It had been fountaining lava more or less continuously since the night of 4 September, its strongest run of activity this year, before the larger explosion early on 6 September. The blast lasted around half a minute. People reported hearing it from up to 700 km away.

Two ash plumes formed. One rose to roughly 6,000 m and drifted northeast across Jakarta, Banten and West Java, which is what put ash over the airports. A second, taller plume reached about 15,000 m and moved west and northwest over Lampung, Bengkulu and the Indian Ocean. Indonesia’s Geological Agency had already raised the volcano to alert level III, or “Siaga”, on 2 July. The 3 km exclusion zone covers residents, visitors, fishermen and climbers. The nearest settlement is more than 16 km from the crater.

On the ground, ashfall was confirmed along the Serang coast in Banten and in Bandar Lampung, where authorities suspended schools and fishing for the day. The national disaster agency, BNPB, urged people not to panic and flew cloud-seeding missions from Pondok Cabe to bring on rain and wash ash out of the air. In the ash-affected areas the agency advised residents to wear masks and eye protection, limit time outdoors, cover water storage and drive with care in the reduced visibility.

Airports Affected

Volcanic ash forced a rolling series of closures across western Indonesia through 6 September, six airports at the peak. Reopening times shifted more than once during the day as the ash cloud moved, so treat the table below as a snapshot rather than a schedule.

The airport operator counted about 301 affected flights, 58 of them international, and authorities named alternative airports for diversions. 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 mid-route. Routes to Singapore, Kuala Lumpur, Hong Kong, Sydney, Seoul, Doha and Amsterdam all saw cancellations, delays or reschedules. The carriers with the most Jakarta departures, among them Indonesia’s flag carrier, moved passengers onto later services once the airport reopened.

How Long the Disruption Lasts

An ash closure is usually measured in hours to about a day, not weeks. It lifts once the eruption pauses and the wind carries the ash clear of the approach and departure paths. The catch is that it can come back: a plume that has drifted away can swing back over an airport if the wind turns, so a reopening is not a guarantee the airport stays open. The cloud-seeding BNPB ran is aimed at shortening that window by raining the ash out.

Even after an airport reopens, the knock-on runs a day or two longer. Aircraft and crews are out of position, slots are backed up, and airlines work through a queue of displaced passengers. If your flight is in the 48 hours after a closure, build in extra time and expect your rebooking options to be tight.

If Your Flight Is Affected

Indonesia’s Transport Ministry has said passengers whose flights were cancelled because of the ash are entitled to a full refund. That sits on top of the standard rules under Ministerial Regulation PM 89 of 2015, which apply whenever a flight is cancelled or heavily delayed:

• Refund or rebooking. The airline must offer either a full refund or a rebooking to the next available flight at no extra cost. The choice is yours.
• Care during long delays. For delays past a few hours the airline owes meals, and accommodation if you are stranded overnight.
• No extra compensation. A volcanic eruption counts as force majeure, so the fixed delay-compensation payments do not apply. The refund and rebooking rights still do.

Check your own flight before you act, because cancelled, delayed and diverted each send you a different way. Your airline’s app updates first, then the airport’s live departures board, then a flight-tracking site. A cancellation puts you into the refund-or-rebook choice above. A long delay means you wait, with meal and hotel cover if it runs late. A diversion, like the Air India flight that returned to Delhi, means the airline decides the next step and you follow its rebooking. Contact the airline directly rather than queueing at the counter, and if you booked through an agent or a third-party site, the refund usually has to go back through them.

Travel Insurance and Volcanic Ash

Whether a policy pays out turns on one date: when you bought it. Once an eruption is in the news, insurers treat it as a known event, and a policy bought after that point will generally not cover disruption from it. A policy bought before the eruption became public is the one that responds.

Cover is not uniform even then. Some policies name volcanic ash and airspace closure as covered events under travel disruption. Others exclude ashfall or “acts of nature” specifically, or cover a cancelled flight but not the knock-on costs of being stranded. An annual multi-trip policy follows the same known-event logic as a single-trip one. If a trip to the region is booked, read the disruption and natural-catastrophe sections of your wording rather than assuming, and keep every receipt for meals and rooms if you end up claiming.

Why Volcanic Ash Closes Airports

Ash is not like fog or a storm. It is finely ground rock and glass. Drawn into a jet engine, it melts in the combustion chamber and then fuses onto the turbine blades as it cools, which can choke the airflow and shut the engine down in flight. It also sandblasts windscreens and clogs sensors. On the ground, a dusting of less than a millimetre on the runway is enough to affect braking. Because the risk is engine failure rather than a rough ride, the response is a hard closure, not a delay. The advisories that trigger it for this region come from the Volcanic Ash Advisory Centre in Darwin, Australia, with AirNav Indonesia and the airlines making the final call.

The Volcanoes That Disrupt Indonesian Flights

Indonesia has more active volcanoes than any other country, and a handful of them close airports on a semi-regular basis. Which hubs are exposed depends on which volcano is active and which way the wind blows.

Bali sits far enough from Java’s big volcanoes that its disruptions have mostly come from the eastern islands, Lewotobi on Flores in particular. Anak Krakatau’s ash goes the other way, toward Jakarta.

Is It Safe to Travel to Bali or Jakarta Right Now?

On the ground, most of the region is unaffected. Bali is about 1,000 km east of the volcano and outside the ash path entirely. Jakarta had ash in the air and disruption at its airports, but only a trace of ashfall in the city, no evacuation, and normal life otherwise. The 3 km exclusion zone is a marine one around an uninhabited island, aimed at boats, fishermen and anyone trying to land for a closer look. The Merak to Bakauheni ferry across the Sunda Strait kept running on a normal schedule, with vessels holding clear of the crater. Anyone with Bali plans this month is well clear of this, and getting to Bali by air was not the focus of the disruption, which centred on Jakarta.

Conditions are different directly under the plume. Along the Serang coast in Banten and around Bandar Lampung, ashfall was light but real, enough for authorities to close schools for the day and advise masks and care on the roads. If your route takes you through those areas in the next few days, expect grit in the air and slower driving rather than danger.

The reason people ask about safety at all is Anak Krakatau’s history. In December 2018 one 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 in that event. Further back, the 1883 eruption of the original Krakatau was one of the deadliest in recorded history. Anak Krakatau, “child of Krakatau”, grew out of the same underwater caldera and first broke the surface in 1927. Authorities have not issued a tsunami warning for the current activity, but the 2018 disaster is why the Sunda Strait coast watches this volcano closely.

How the Current Activity Escalated

This is not a sudden event. The Geological Agency lifted Anak Krakatau to alert level III on 2 July 2026 after a run of eruptions, and it has stayed there since. Activity stepped up sharply from 4 September with sustained lava fountaining, then came the 6 September explosion that reached the stratosphere on the Sumatra side. Level III is the second highest rung on Indonesia’s four-step scale. Level IV, the top, would signal an eruption in progress or imminent with wider evacuation. The volcano has not been placed at Level IV.

Official Sources to Check

For the current status, these sources are worth more than news aggregators:

• Magma Indonesia. The Geological Agency’s official volcano monitoring portal and app, with daily activity reports and the current alert level for every Indonesian volcano.
• Darwin VAAC. The Australian Bureau of Meteorology runs the volcanic ash advisory service that airlines fly by, showing current ash-cloud position and forecast movement.
• BNPB. Indonesia’s national disaster agency issues the on-the-ground updates: ashfall areas, school and port closures, and response operations.
• Your airline and the airport operator. Flight status and rebooking open up on the airline’s app first. The airport’s own channels confirm whether it is open.