Anak Krakatau eruption disrupts nearly 3,000 flights across Indonesia

Volcanic Eruption

Severity score13 / 100 · Watch

How the score is calculated

The score starts at 8. It adds points from recorded affected, deaths, displaced and casualty counts, plus terms found in the story title, event type or status. For each count, only its highest matching band is used.

Affected people: 1–999: +5 · 1,000–9,999: +12 · 10,000–99,999: +20 · 100,000–999,999: +28 · 1 million+: +35
Deaths: 1–9: +8 · 10–99: +14 · 100–999: +22 · 1,000+: +30
Displaced people: 1–9,999: +6 · 10,000–99,999: +12 · 100,000+: +18
Casualties: 100 or more: +8
Story wording: +10 for terms such as catastrophe, famine, war, conflict, major earthquake, mass casualty or critical. Otherwise, +5 for active, ongoing, emergency, outbreak, cyclone or hurricane.

Score bands: Watch 0–24 · Moderate 25–49 · High 50–74 · Critical 75–100. Scores are capped at 100. Missing or unparseable figures add no points.

This is a rule-based WorldsAid triage indicator, not an official or independently validated classification. It does not account for recency or local context, and it can understate events with incomplete reporting. Check the linked sources.

Last verified8 Sept 2026

Date: 8 Sept 2026
Status: GDACS ORANGE · ALERT LEVEL III · MONITORING ONGOING
Aid Zone: ASIA
Countries: Indonesia
Agency: PVMBG / BMKG / GDACS

In brief

What happenedA sustained eruption of Anak Krakatau in Indonesia's Sunda Strait sent volcanic ash across parts of Java and Sumatra, disrupting aviation and prompting authorities to maintain heightened monitoring.
How many affectedGDACS alert: Orange · Flights disrupted: Nearly 3,000 · Passengers initially stranded: About 170,000
What help is neededResponse priorities should be confirmed in the linked source reports as needs change.

What changed

First retained snapshot

No earlier verified snapshot is present in the recovered dataset. This record remains available as the historical baseline.

Situation

A sustained eruption of Anak Krakatau in Indonesia's Sunda Strait sent volcanic ash across parts of Java and Sumatra, disrupting aviation and prompting authorities to maintain heightened monitoring. Indonesia's Geological Agency said the continuous eruptive episode lasted about 25 hours, from late on 4 September until shortly after midnight on 6 September. Smaller intermittent Strombolian eruptions continued afterward, and the volcano remained at Alert Level III (Siaga), with residents, visitors and climbers instructed to stay at least three kilometres from the active crater.

Ash forced the temporary closure of eight airports, including Jakarta's Soekarno-Hatta and Halim Perdanakusuma airports. The disruption halted or affected nearly 3,000 flights and initially stranded about 170,000 passengers, according to Associated Press reporting based on Indonesian authorities. By 8 September, Indonesia's meteorological agency BMKG said paper tests were negative for volcanic ash at the affected airports and confirmed that all eight had resumed operations. Ash was still being monitored at heights of up to 7,000 feet, moving south-southwest at 5–10 knots.

GDACS classified the eruption as an Orange Alert. Its exposure model estimates about 2,000 people live within 30 kilometres of the volcano and approximately 7.77 million within 100 kilometres; these are exposure estimates, not reported numbers of people harmed. No casualties or evacuation order had been reported. BMKG said monitoring through 20 tsunami gauges and a coastal radar array found no abnormal sea-level signal, while officials continued surveillance of volcanic activity, ash dispersion and aviation conditions. Figures and operating conditions may change if eruptive activity intensifies.

Linked charities and agencies

GDACS · Organisation profile

WorldsAid verification

A WorldsAid editor reviewed this record against 4 attributed sources, cleaned feed formatting and checked the crisis, place and reporting date. 9 human-impact figures were separated from the narrative and dated where the source allowed. Earlier observations remain in the evidence history instead of being silently overwritten.

Verified figures

GDACS alert: Orange retained at 2026-09-08
Flights disrupted: Nearly 3,000 retained at 2026-09-08
Passengers initially stranded: About 170,000 retained at 2026-09-08
Airports temporarily closed: 8 · all reopened by 8 September retained at 2026-09-08
Official alert level: Level III (Siaga) retained at 2026-09-08
Exclusion zone: 3 km from the active crater retained at 2026-09-08
Population within 30 km: About 2,000 · GDACS exposure estimate retained at 2026-09-08
Reported casualties: None retained at 2026-09-08
GLIDE number: VO-2026-000171-IDN retained at 2026-09-08

What we knew when

2026-09-08WorldsAid record entered the retained historical dataset.
2026-09-08Last verification represented by this immutable snapshot.

Earlier figures are never replaced by later values; additional observations are retained as new ledger entries.

Provenance

This page renders the last verified WorldsAid cache directly in HTML. It does not treat generated summaries as primary evidence.

Cached dataset: worldsai_drup771.sql.gz

Record integrity:

Verified

SHA-256 53d910c0abc7db62878c9a437cc44f9868621c0ee113ef0019641debdf9b831c

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