Indonesia lowers Anak Krakatau alert after activity declines
Indonesia lowered Mount Anak Krakatau’s alert from Level III to Level II on September 21 after volcanic activity and deformation declined. A two-kilometre exclusion zone remains in place.
By DoomRadar · Published on DoomRadar . Updated .
Based on two sources with available article excerpts. Source-linked claims are not independent confirmation.
What happened
Indonesia’s Geological Agency lowered Mount Anak Krakatau’s alert from Level III to Level II on September 21, 2026, at 6:30 p.m. Jakarta time. [1][2]
References for this detail (2)
- Indonesia Lowers Anak Krakatau's Alert Statusen.tempo.co · Recorded source date: Sep 21, 2026, 8:47 PM UTC
- Status Gunung Anak Krakatau Turun dari Siaga Menjadi Level II Waspadakoran-jakarta.com · Recorded source date: Sep 22, 2026, 2:17 AM UTC
The volcano recorded 224 eruptions through September 3 and a continuous eruptive episode lasting about 25 hours from September 4 to September 6. [1][2]
References for this detail (2)
- Indonesia Lowers Anak Krakatau's Alert Statusen.tempo.co · Recorded source date: Sep 21, 2026, 8:47 PM UTC
- Status Gunung Anak Krakatau Turun dari Siaga Menjadi Level II Waspadakoran-jakarta.com · Recorded source date: Sep 22, 2026, 2:17 AM UTC
Activity had declined after continuous eruptions stopped on September 20; officials cited deflation data, while seismic records showed one low-frequency earthquake and average continuous tremor amplitude of 2 millimetres on September 20. [1]
References for this detail (1)
- Indonesia Lowers Anak Krakatau's Alert Statusen.tempo.co · Recorded source date: Sep 21, 2026, 8:47 PM UTC
Residents, visitors, tourists and climbers remain barred from entering or conducting activities within two kilometres of the crater. [1]
References for this detail (1)
- Indonesia Lowers Anak Krakatau's Alert Statusen.tempo.co · Recorded source date: Sep 21, 2026, 8:47 PM UTC
Context from the sources
The volcano had been placed at Level III on July 2 because of increased seismicity and deformation. [1][2]
Earlier eruptions produced lava flows toward the northwest, west and southwest, and ash reached Greater Jakarta, prompting closures at several airports, according to the reported account. [1]
Explore the sources and reporting timeline
2 source links · 2 domains
These counts describe the references, not independent confirmations. Different outlets can repeat the same original report.
Source timeline
Oldest to newest among the available source dates, not a chronology of the incident. Article publication dates come from the source; other recorded dates may reflect when a link was found.
- [1] Indonesia Lowers Anak Krakatau's Alert Statusen.tempo.coReferenced for: detail 1, detail 2, detail 3, detail 4
- [2] Status Gunung Anak Krakatau Turun dari Siaga Menjadi Level II Waspadakoran-jakarta.comReferenced for: detail 1, detail 2
What this could mean for you
Access to the volcano area may remain restricted for visitors and climbers.
The standing two-kilometre crater exclusion zone prevents activities close to the volcano.
Reported basis: [1] · The possible effect is interpretation.
Depends on: Authorities must maintain or expand the exclusion zone.
Possible time frame: days, if those conditions hold.
Flights or airport operations could face disruption if ash emissions intensify again.
The reported earlier ash reached Greater Jakarta and was linked to closures at several airports.
Reported basis: [1] · The possible effect is interpretation.
Depends on: Volcanic ash must again reach aviation routes or airports.
Possible consequences, not a forecast. Their relevance depends on your location and the conditions above.
For your country
Choose a country to check how this event could affect you.
What changes the outlook
Risk increases if…
Renewed increases in eruptions, tremors or deformation could lead authorities to raise the alert level again.
Ash emissions affecting populated areas or aviation could broaden travel disruption.
Pressure eases if…
Continued low seismicity, declining tremor and further deflation could support continued access restrictions being reduced.
Authorities could lift the two-kilometre exclusion zone after reassessing volcanic conditions.
Still unclear
The sources do not establish whether any airports remain affected after the alert reduction.
The sources do not provide a forecast for how long the lower activity will continue.
Market implications
Market impact
Sources (2)
References for the reported details. Separate links do not necessarily mean independent confirmation.
Available excerpt
TEMPO.CO, Jakarta - The volcanic activity level of Mount Anak Krakatau has been lowered to Alert Level II on Monday, September 21, 2026, at 6:30…A short excerpt from our source record; open the original for the full article.
Available excerpt
Jakarta - Badan Geologi Kementerian Energi dan Sumber Daya Mineral (ESDM) menurunkan tingkat aktivitas Gunungapi Anak Krakatau di Selat Sunda, dari Level III (Siaga) menjadi…A short excerpt from our source record; open the original for the full article.
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