Indonesia’s Anak Krakatau has once again shown that volcanoes have little respect for airline schedules, carefully planned holidays, or Monday morning meetings.
The volcano’s latest eruption in the Sunda Strait has sent ash across parts of western Indonesia, forcing airport closures, disrupting thousands of flights, and turning one of Southeast Asia’s busiest aviation systems into a rolling exercise in contingency planning.
By 9 am WIB on Monday, 7 September, InJourney Airports data reported by Indonesian media showed that 2,300 flights and 268,539 passengers across its airport network had been affected as a consequence of the temporary closure of four major airports: Soekarno-Hatta International Airport, Halim Perdanakusuma Airport, Radin Inten II Airport and Husein Sastranegara Airport. Soekarno-Hatta alone accounted for 1,320 affected flights and 173,474 passengers.
Those figures superseded an earlier Indonesian Transport Ministry tally on Sunday evening of 1,558 delayed flights and about 170,000 passengers held up across eight affected airports. At that point, Soekarno-Hatta accounted for 963 affected flights, 453 arrivals and 510 departures.
For travellers, the arithmetic is unpleasant enough. For airlines, airports and travel agents, it is a reminder that volcanic ash can turn an apparently straightforward itinerary into a masterclass in improvisation.
And unlike a late catering truck, a volcano cannot be hurried along.
Seven airports remain closed as ash risk continues
Indonesia’s aviation authorities have repeatedly extended closures as volcanic ash moved through affected airspace.
By Monday morning, seven airports remained closed until an estimated 6 pm WIB: Soekarno-Hatta, Halim Perdanakusuma, Radin Inten II, Husein Sastranegara, Budiarto, Pondok Cabe and Muhammad Taufiq Kiemas. Atung Bungsu Airport in Pagar Alam has returned to normal operations.
The position remains dynamic. AirNav Indonesia and airport authorities have stressed that reopening decisions depend on actual airspace and airport conditions, not a timetable set well in advance.
That distinction matters.
An estimated reopening time is exactly that: an estimate.
Volcanic ash does not consult the departure board.
The closures follow a prolonged eruptive episode at Anak Krakatau that began at 11.07 pm WIB on Friday, 4 September, and ended at 12.04 am WIB on Sunday, 6 September, according to Indonesia’s Centre for Volcanology and Geological Hazard Mitigation, PVMBG.
The continuous episode lasted about 25 hours. Indonesia’s Energy and Mineral Resources Ministry reported on Monday that Anak Krakatau had since returned to lighter, intermittent Strombolian eruptions. Seismic activity nevertheless remained elevated, and authorities said the likelihood of further eruptions in coming periods remained high.
Crucially, the volcano remains at Level III, or Siaga – Watch, and a three-kilometre exclusion zone around the centre of volcanic activity remains in force.
Authorities continue to warn of hazards including incandescent ejecta, heavy ashfall and potential lava flows if sustained eruptive activity resumes.
Qantas Jakarta flights caught in the disruption
Australian travellers have been directly affected.
Qantas confirms that QF39, QF40, QF41 and QF42 have been impacted by the Anak Krakatau eruption.
The airline is offering additional flexibility to customers who booked Qantas flights to or from Jakarta on or before 5 September for travel between 5 and 9 September inclusive.
Eligible passengers can request a fee-free refund, travel credit or date change of up to seven days from the original date of travel, subject to availability.
Qantas’ published volcanic-disruption notice relates specifically to its Jakarta services. Nevertheless, airline networks do not operate as isolated pieces on a chessboard. Aircraft, crews, and connecting passengers move through systems, so closing a major gateway such as Jakarta can create consequences elsewhere.
Singapore Airlines has also cancelled a series of Singapore–Jakarta and Jakarta–Singapore flights because of Anak Krakatau, including SQ968 on 6 September and numerous services on 7 September.
Singapore Airlines Anak Krakatau advisory
For passengers holding connecting itineraries, the advice is refreshingly old-fashioned: check the airline before leaving for the airport.
Arriving three hours early is useful when an aircraft is operating.
It is less transformative when the runway is closed.
Why volcanic ash is an aviation problem
Volcanic ash is not simply inconvenient grey dust.
Fine ash particles can abrade aircraft windscreens, contaminate ventilation and other aircraft systems and, in sufficient concentration, seriously damage turbine engines.
That is why airlines, airport operators and air-navigation authorities make conservative decisions when volcanic ash is detected.
From a passenger perspective, an airport closure can be frustrating.
From an operational perspective, the equation is rather simpler: jet engines and concentrated volcanic ash make particularly poor travelling companions.
Indonesia’s Transport Ministry has also reminded airlines that they must handle passengers affected by airport closures in accordance with applicable regulations, including providing information about changes in flight status and available alternatives.
Authorities prepared alternative airports including Kertajati, Juanda, Yogyakarta International Airport and airports serving Semarang and Solo. Ground transport was also made available where airlines moved operations.
InJourney Airports additionally made free buses available from Soekarno-Hatta to Yogyakarta, Solo, Semarang and Surabaya as part of its passenger service-recovery response.
It may not have been the itinerary passengers originally had in mind, but in disruption management, movement beats mystery.
Smartraveller warns Australians to keep checking flights
Australia’s Smartraveller service updated its Indonesia advice on 6 September to address Anak Krakatau specifically.
It warns that volcanic ash from the volcano has affected operations at major airports, including Soekarno-Hatta International Airport in Jakarta, and says airports in affected areas may close at short notice.
Australian travellers are advised to monitor their flight status closely and confirm any changes directly with their airline or travel provider before travelling.
Smartraveller also warns that volcanic ash may affect air quality. Travellers with asthma or other respiratory conditions are advised to take particular care and follow local health advice.
Australian Government Smartraveller Indonesia advice
For the Australian travel trade, the practical message is straightforward: check official aviation information, check the airline, and check Smartraveller before sending clients to an airport caught in an evolving ash event.
Social media may tell you that somebody’s cousin saw an aeroplane take off.
A NOTAM is generally more useful.
No current indication of a tsunami-scale collapse
Anak Krakatau inevitably carries a darker historical association.
The volcano sits in the Sunda Strait between Java and Sumatra and grew within the submerged caldera left by the catastrophic 1883 Krakatau eruption.
Eruptions beginning in 1927 built the cone that became known as Anak Krakatau, literally the “Child of Krakatau”. US Geological Survey records describe eruptions beginning in December 1927 as building the new cone within the 1883 caldera.
In December 2018, a partial collapse of Anak Krakatau generated a devastating tsunami that struck coastal communities in Java and Sumatra and killed hundreds of people.
That history understandably makes renewed activity headline material.
However, Indonesia’s Geological Agency has made an important distinction about the present activity.
Its assessment says the volcanic body that has rebuilt since the 2018 collapse remains relatively small and does not currently have the potential to collapse on a scale capable of generating a tsunami.
Authorities are continuing to monitor changes in the volcano’s morphology closely.
The present danger should therefore neither be minimised nor inflated into something authorities have not reported.
The immediate travel issue is ongoing volcanic activity, ash already dispersed through the atmosphere and the consequences for aviation and air quality.
Too late to buy cover? Anak Krakatau renews insurance warning
The eruption also brings another familiar travel problem sharply into focus: buying travel insurance after the event a traveller wants protection from has already become known.
Compare the Market data supplied to Global Travel Media, based on travel-insurance quote trends between May 2023 and March 2026, shows significant increases in consumer interest immediately after major disruption events.
The company says it routinely sees jumps in quote activity following fires, floods, volcanic eruptions and geopolitical disruption.
According to the data supplied to Global Travel Media, when volcanic activity disrupted Bali-bound travel in November 2024, travel-insurance quote volumes rose 32 per cent above average.
There is a geographical point worth getting right.
The November 2024 aviation disruption affecting Bali was caused by the eruption of Mount Lewotobi Laki-laki on Flores, not by a volcano located in Bali itself.
Ash from that eruption nevertheless caused widespread cancellations affecting services to and from Bali.
Travellers did not need to be anywhere near the volcano to discover that ash travels rather better than most passengers.
Compare the Market GM Media & Communications Chris Ford said the tendency for travellers to buy insurance the night before departure, or only after a disruptive event hits the headlines, was concerning.
“If you’re buying insurance after a disaster is declared in an area you’re travelling to, you’re simply too late,” Mr Ford said. “Once something becomes a ‘known event’ it gets excluded from new policies – otherwise it would be impossible for insurers to keep up with claims.
“It’s a good idea to get into the habit of buying insurance as soon as you’ve booked your flights or accommodation. That way, you’re also covered for anything that happens in the lead up to your holiday, as well as issues that occur while you’re abroad.”
The broad principle is consistent with Compare the Market’s publicly available travel-insurance guidance.
It says most travel insurance policies cover unforeseen events, and an event already known when a policy was purchased may not be covered. Once an event has received widespread media coverage or generated an official travel warning, an insurer may reasonably regard it as a known event.
Compare the Market travel insurance information
That does not mean every policy treats volcanic activity in precisely the same way.
Coverage varies between insurers and products, and travellers should check the Product Disclosure Statement, policy limits, exclusions, excesses and any requirements relating specifically to natural-disaster or volcanic-ash cover.
The words “comprehensive travel insurance” are useful.
They are not a magic spell.
Compare the Market experts analysed travel insurance quote trends between May 2023 and March 2026
Buy insurance early and understand what it covers
The practical lesson from Anak Krakatau is not simply to buy insurance.
It is to buy suitable cover early enough for its cancellation component to have value and then understand exactly what that cover provides.
A traveller who buys an appropriate policy soon after booking flights or accommodation may have protection for certain unforeseen events arising before departure, subject to the policy wording.
A traveller who waits until a volcano is erupting, airports are closing, and the event is appearing in government travel advice may find that losses connected with that event are already excluded from a newly purchased policy.
That is the logic behind the known-event principle.
Insurance transfers uncertain risk.
It is not designed to turn yesterday’s headline into tomorrow’s unexpected event.
Travellers who already hold insurance should also avoid assuming that every additional expense will automatically be reimbursed.
They should check their policy, keep receipts, retain airline cancellation or delay notifications, and contact their insurer whenever clarification is required.
Where an airline, hotel or another supplier provides a refund or rebooking, travellers may also be required to pursue that option before claiming the same loss through insurance.
For travel agents, the lesson is equally clear: insurance belongs near the start of the booking conversation.
It should not be the final hurried question after seat selection.
A major test for airlines, airports and travel advisers
The Anak Krakatau disruption is also a test of service.
For airlines and airports, volcanic activity is beyond their control.
Communication is not.
Passengers will generally tolerate bad news better than no news. Clear rebooking options, visible staff, accurate updates and sensible recovery arrangements can make the difference between a disrupted journey and a thoroughly miserable one.
For travel advisers, the episode reinforces the value of professional support.
Travellers with complicated itineraries, cruises, tours or separately ticketed connections can face a chain reaction when a major gateway suddenly closes.
Jakarta is both one of Southeast Asia’s major business centres and an important regional aviation hub.
Disruption there does not remain neatly contained within Jakarta.
It spreads through aircraft rotations, connecting flights, hotel bookings, corporate travel schedules, domestic networks and onward journeys throughout Asia.
That is why the best response remains remarkably traditional: monitor authoritative sources, communicate early and keep alternatives open.
Anak Krakatau quietens, but the travel risk remains
The most intense 25-hour continuous eruptive episode has ended, but that should not be mistaken for an all-clear.
Indonesia’s Energy and Mineral Resources Ministry said on Monday that lighter Strombolian eruptions had continued after the prolonged episode ended, while seismic activity remained elevated.
Anak Krakatau therefore remains at Level III, and authorities say the likelihood of further eruptions remains high.
The three-kilometre exclusion zone remains in place.
Meanwhile, volcanic ash already dispersed into the atmosphere can keep affecting aviation even after an eruption’s character or intensity changes.
For travellers, that means airport status and airline schedules may continue moving faster than yesterday’s news report.
The broader lesson is uncomplicated.
Volcanoes are part of Indonesia’s geological reality. They are also one reason travellers, airlines and travel advisers require sensible contingency planning.
Check the official warning.
Check the airline.
Buy suitable travel insurance before trouble becomes a known event.
And when a volcano in the Sunda Strait begins rearranging aviation across western Indonesia, perhaps accept that the departure board is making suggestions rather than promises.
Because nature, as ever, retains the final boarding call.
By: Stephen Peters – © 2026.
Read Time: 9 minutes.
Author Bio:
Stephen Peters has spent much of his career proving that the straight-and-narrow path is considerably overrated. Armed with a Bachelor’s degree in Technology from the University of Queensland and a Master’s in Management, he first ventured into hospitality, working in and helping open several five-star hotels across Sydney and Asia.
After deciding he had experienced quite enough of five-star hospitality from the operational side of the desk, Stephen returned to technology, working with major US tech companies while based between Australia and Asia.
Then came the ultimate change of scenery. Stephen built his own yacht and, with his family aboard, sailed from Florida through the United States and its Great Lakes before crossing the Pacific to Asia. Several memorable years followed, exploring Indonesian waters before the Peters family eventually returned to Australia with considerably more sea miles, stories and perspective than when they left.
