Mount Anak Krakatau’s eruption in the Sunda Strait triggered flight disruptions at eight Indonesian airports, resulting in more than 1,558 flights delayed or cancelled as of September 7, 2026. The episode caused widespread travel interruption with thousands of travelers stranded.
Volcanic Ash Spreads Across Java and Sumatra
Volcanic ash clouds from Anak Krakatau extended over the airspace of Java, Sumatra, Banten, Jakarta, West Java, and parts of Sumatra, prompting safety-driven closures of airports including Soekarno-Hatta International Airport and Halim Perdanakusuma Airport. Soekarno-Hatta alone saw over 900 flights delayed or cancelled due to ash contamination threats.
AirNav Indonesia shut the airspace surrounding these airports as a precaution. The
Indonesia Meteorology, Climatology and Geophysical Agency (BMKG) actively monitored ash movement and issued aviation warnings covering the impacted regions.
Eruption Timeline and Alert Status
The eruption episode lasted roughly 25 hours, beginning late on Friday, September 4, 2026, and ending early on Sunday, September 6. Notable bursts included a 30-second eruption at 3:53 a.m. on September 6 and a 16-second eruption three hours later. Indonesia’s Geological Agency reported ongoing volcanic activity and maintained the volcano at Level III (Siaga) alert.
An exclusion zone remains enforced around Anak Krakatau’s crater, with authorities cautioning against public entry due to volcanic hazards.
Flight Disruptions and Passenger Impact
Initial reports from Indonesia’s Ministry of
Transportation indicated approximately 170,000 passengers affected by the disruptions. Reuters later updated these figures to over 2,300 flights disrupted and more than 270,000 travelers impacted. The widespread airport closures and flight cancellations left many passengers stranded and scrambling for alternatives.
Delays and cancellations fluctuate as volcanic ash movement remains unpredictable, influenced by wind and weather conditions. This leads to rolling airport closures without fixed reopening times.
Official Responses and Safety Priorities
Indonesia’s Directorate General of Civil Aviation has coordinated closely with airlines, airports, BMKG, and AirNav Indonesia to monitor conditions and manage flight operations amid the ash threat. Lukman F. Laisa, the Ministry of Transportation’s
director general of civil aviation, stated, “Safety remains our top priority in every operational decision.”
BMKG continues 24/7 tracking of volcanic ash clouds, issuing timely aviation warnings based on ash dispersion. Authorities emphasize ongoing vigilance due to the possibility of further eruptions at Anak Krakatau.
Indonesia’s Volcanic Activity Context
Anak Krakatau, a volcano in the Sunda Strait and descendant of Krakatau, has intensified activity since July 2026, culminating in the strong September eruption. Indonesia’s position on the Pacific Ring of Fire exposes it to frequent volcanic and seismic incidents. While volcanic disruptions to aviation are not uncommon, the current scale, particularly affecting the major
hub at Jakarta, marks a significant episode in 2026.
