Anak Krakatau's Days-Long Eruption Grounded Thousands of Flights in Indonesia

A powerful, more than 24-hour eruption from Indonesia's Anak Krakatau volcano sent ash and gas high into the atmosphere in early September 2026, disrupting thousands of flights and degrading air quality in parts of the country, including the capital, Jakarta. Anak Krakatau sits between the islands of Java and Sumatra and erupts regularly, though usually far more mildly than this.

Satellites captured the explosive activity on September 5. Images from the OLI instrument on the NASA-USGS Landsat 8 satellite showed a white plume of volcanic gas billowing over a brown ash cloud, while the VIIRS instrument on the Suomi NPP satellite captured a wider view of the volcanic material dispersing over a large area. Indonesia's meteorological agency, BMKG, reported that by September 6, ash had reached altitudes of up to 6,000 metres (20,000 feet) to the east of the volcano and 15,000 metres (50,000 feet) to the west.

The ash prompted the temporary closure of eight airports on Java and Sumatra, disrupting nearly 3,000 flights, and the BBC reported that 340,000 people were left stranded. Ashfall affected populated areas, particularly east of Anak Krakatau in Jakarta and other parts of West Java, according to the Indonesian Humanitarian Coordination Platform, which noted that volcanic ash can irritate the respiratory tract, eyes and skin and poses different risks than smoke from the peatland fires that also affect the country.

On September 6, the continuous explosive eruption subsided, though the volcano kept rumbling, and it returned to a more typical pattern of intermittent ash bursts known as Strombolian eruptions. Airports had resumed operation by September 8, but the volcano remained at the second-highest alert level on Indonesia's scale, where it has stood since early July.