Will Anak Krakatau Keep Disrupting Singapore–Jakarta Flights?

Persistent eruptions at Indonesia’s Anak Krakatau volcano have closed Jakarta’s key airports and forced dozens of cancellations on the busy Singapore–Jakarta route, raising concerns over how long travelers will face disruption.

Flight cancellations mount as ash cloud lingers

Jakarta’s Soekarno-Hatta and Halim Perdanakusuma airports remain temporarily closed on September 7, following major eruptions at Anak Krakatau that began intensifying in early September. Indonesian transport authorities have extended closures for multiple airports in western Indonesia, citing drifting volcanic ash in the Sunda Strait region and over Java’s main aviation corridors.

Publicly available information indicates that more than 2,000 flights across Indonesia have been disrupted since the weekend, affecting hundreds of thousands of passengers. A significant share of these are international and domestic services linked to the Jakarta hub, including routes to and from Singapore that typically operate at high frequency.

Singapore–Jakarta services have been among the hardest hit. Channel NewsAsia reports that at least 60 flights between the two cities were canceled on September 6 alone, after ash clouds forced an initial closure of Jakarta’s main gateway and triggered widespread schedule changes at Singapore’s Changi Airport.

With volcanic ash still detected in the atmosphere over parts of western Indonesia as of September 7, airlines are continuing to trim or reroute operations. The situation remains fluid, with carriers issuing rolling advisories and urging passengers to monitor flight status closely.

Airlines adjust Singapore–Jakarta schedules day by day

Major regional airlines have already outlined extensive adjustments on the Singapore–Jakarta corridor. Scoot’s latest advisory lists the cancellation of a full day’s worth of flights between Singapore and Jakarta on September 6, covering multiple morning and evening rotations as a precaution in response to ash near the flight path.

AirAsia has likewise reported that all of its flights to and from Jakarta were canceled or rescheduled on September 6 following the closure of Soekarno-Hatta International Airport. The carrier notes that ash dispersion has also required adjustments on other routes that typically cross airspace affected by the Anak Krakatau plume.

Singapore Airlines has issued separate guidance showing selected Singapore–Jakarta services canceled on September 6, alongside advice for passengers to check flight status pages for the most up-to-date information. At Changi Airport, media coverage and eyewitness accounts describe long queues at airline counters as travelers seek rebooking options or alternative routings via other Indonesian cities.

Analysts following the region’s aviation market highlight that the Singapore–Jakarta route is one of Southeast Asia’s busiest international city pairs. Any prolonged disruption, even over a few days, can quickly lead to aircraft and crew rotations being out of position, which may cause knock-on delays and cancellations even after airports begin to reopen.

Volcanic ash and aviation: why closures can extend beyond eruptions

Specialist hazard centers and meteorological agencies explain that volcanic ash poses severe risks to jet engines, windscreens, and aircraft systems. The Darwin Volcanic Ash Advisory Centre, which oversees this part of Southeast Asia, has issued multiple advisories since early September tracking Anak Krakatau’s ash plume at flight levels used by commercial aircraft.

Indonesia’s meteorology and geophysics agency BMKG reports that Anak Krakatau’s activity has increased since July, with eruptions in early September sending ash up to high altitudes and drifting mainly west and southwest of the volcano. Monitoring has been stepped up to 24 hours a day, with ash distribution tracked via satellite imagery and ground-based observations.

Because ash clouds can move independently of visible eruptive activity, airspace closures often remain in place after explosive pulses subside. Forecast products from advisory centers model how ash is likely to disperse over several hours, and aviation authorities tend to keep restrictions in force until they are confident that concentrations along key routes fall below safety thresholds.

For travelers, this means that even if Anak Krakatau appears quieter on a given day, Singapore–Jakarta flights may still be cancelled or rerouted if lingering ash continues to intersect standard airways. Airlines generally err on the side of caution, preferring ground delays over the risk of flying through contaminated airspace.

How long could the Singapore–Jakarta disruption last?

Historical patterns at Anak Krakatau and other Indonesian volcanoes suggest that elevated activity can persist for weeks or months, with phases of stronger and weaker eruptions. Recent scientific work on Anak Krakatau’s evolution notes a tendency toward intermittent but sometimes high-intensity explosive phases, which can produce recurrent ash emissions affecting nearby air routes.

Disaster-monitoring platforms classify the current Anak Krakatau event at an intermediate alert level for aviation, indicating a significant but localized hazard. Advisories from early September describe ash rising to cruising altitudes typically used by medium-haul jets, but confined mainly to western Indonesia and the Sunda Strait rather than spreading across the wider region.

Aviation analysts point out that several factors will determine how long Singapore–Jakarta flights remain disrupted: the volcano’s eruptive intensity, upper-level wind patterns that control ash drift, and the speed at which Indonesian authorities can verify safe conditions around Jakarta’s airspace. If eruptions weaken and winds shift, airports could reopen in stages and airlines might restore most flights within days, albeit with residual delays.

However, if Anak Krakatau continues to produce frequent ash-rich explosions, intermittent closures may recur. In that scenario, carriers on the Singapore–Jakarta route may adopt a more conservative scheduling approach, publishing reduced frequencies and building in buffers for diversions until activity clearly subsides.

What travelers should expect in the coming days

In the short term, passengers booked between Singapore and Jakarta should be prepared for ongoing disruption, especially through the week of September 7. Given the evolving nature of the ash cloud, airlines are updating operations in near real time rather than announcing long-term cancellations for the route.

Public advisories from Indonesian transport authorities emphasize that airport reopenings will only proceed once safety can be assured. That suggests a cautious, phased resumption of flights, with priority likely given to clearing backlogs of stranded travelers and restoring domestic connectivity through Jakarta’s hub before schedules fully normalize.

Travel industry observers recommend that passengers allow extra time for connections, consider flexible or refundable tickets where possible, and explore alternative routings via other Indonesian cities such as Surabaya or Bali if travel is essential. Travelers are also encouraged to monitor airline websites, mobile apps, and airport notices rather than relying solely on booking confirmations issued before the latest eruption phase.

While there is no firm timeline for a full return to normalcy on the Singapore–Jakarta route, current assessments indicate that disruptions are likely to be measured in days and potentially intermittent weeks rather than months, provided Anak Krakatau does not escalate into a significantly larger eruptive episode.

Channel NewsAsia coverage of Singapore–Jakarta flight cancellations

Scoot advisory on flights affected by Anak Krakatau eruption

AirAsia update on flights impacted by Anak Krakatau

Singapore Airlines advisory on Anak Krakatau-related disruptions

Smithsonian Global Volcanism Program: Krakatau activity background