Krakatau's eruption grounded 1,558 flights — what it actually costs your Jakarta or Bali trip

Mount Anak Krakatau's biggest eruption of its five-month unrest shut eight airports across western Indonesia on 5-6 September, including Jakarta's Soekarno-Hatta — the country's main international gateway — for more than 30 hours. Indonesia's transport ministry counted 1,558 delayed or cancelled flights and roughly 170,000 stranded passengers, with international routes to and from Hong Kong, Seoul, Doha, Amsterdam and Kuala Lumpur among those disrupted. The volcano has sat at Alert Level III, the second-highest tier, since 2 July, and erupted ten times in a single week in mid-August. This isn't a one-off; it's a live risk category for anyone with a Jakarta or Bali trip booked before year-end. Here's what it actually costs, and what it doesn't.

A volcano that's now erupting on a schedule

Since the Level III alert went up in July, Anak Krakatau has produced repeated ash events, culminating in Saturday's eruption, which sent a plume to roughly 15km (50,000ft) and triggered a 3-5km exclusion zone around the crater. Treat the rest of 2026 the way you'd treat Japan's typhoon season: not a single bad-luck day, but a recurring weather pattern you should book around.

Jakarta's waiver, and the Bali gap

Cathay Pacific issued a fee-free rebooking, rerouting and refund waiver for tickets issued on or before 5 September for travel to or from Jakarta — worth roughly HK$1,200 on its own, since that's Cathay's standard Economy Light change fee, plus whatever fare difference a same-day rebooking would otherwise cost. But the waiver is scoped to Jakarta. Bali's Ngurah Rai airport stayed open through the eruption, absorbing about 42 disrupted movements, mostly on the Bali-Jakarta domestic leg, while the roughly 21-times-a-week Hong Kong-Denpasar service (split between Cathay Pacific and Hong Kong Airlines, from around HK$3,900 return) kept flying uninterrupted. If the next Level III eruption drifts ash toward Denpasar instead of Jakarta, a Bali booking sits outside any waiver currently on the books until the airline separately extends one — worth checking before you assume Jakarta's fee waiver covers you too.

What Indonesian law actually pays you

Indonesia's Consumer Protection Law and Ministry of Transportation Regulation 89/2015 entitle you to a refund or free rebooking, plus meals and accommodation once a delay passes three hours. There's no EU261-style cash payout for the disruption itself — the same conclusion Japan's own delay rules forced in our August typhoon coverage. So the real exposure for a Hong Kong traveller isn't a compensation cheque you're owed and won't get; it's a forfeited non-refundable hotel night or a burnt day of a short trip, since the airline's obligation stops at getting you there, not at making you whole for what the delay cost you.

Is it still worth booking

None of this touches the underlying currency case: the rupiah remains near its record low against the US dollar, which we covered here in early September, so Jakarta and Bali are still cheap by recent-history standards in HKD terms. What's changed is the risk premium attached to that trade. If you're travelling in the next month while Level III holds, book a refundable rate for your first one or two hotel nights — the marginal cost is typically 10-20% over the non-refundable price — and check whether your ticket actually falls inside a live waiver window rather than assuming Indonesian consumer law will backstop a non-refundable loss it was never designed to cover.