Ash plume from Semeru volcano reaches 4 300 m (14 100 feet) a.s.l., Indonesia

Volcanic ash from Semeru in Indonesia was observed at 4 300 m (14 100 feet) above sea level at 03:10 UTC on October 29, 2025. The advisory was issued by the Darwin VAAC at 03:30 UTC.

According to the VAAC advisory, ground reports indicated intermittent discrete eruptions were ongoing, although volcanic ash could not be identified on satellite imagery due to meteorological cloud cover. The ash cloud was detected at flight level 140, which corresponds to approximately 4 300 m (14 100 feet) above sea level, and was reported moving southwest at 9 km/h (5.6 mph). The current Aviation Color Code is Orange.

Recent activity reported by the Global Volcanism Program noted that Semeru experienced daily eruptive events during the week of September 24-30, 2025. White-and-gray or gray ash plumes rose 400-900 m (1 300–3 000 feet) above the summit. The Alert Level remained at 2, with warnings to avoid areas within 3 km (1.9 miles) of the summit, 8 km (5 miles) to the southeast, and specific river drainages due to lahar and pyroclastic flow hazards.

Semeru is a large stratovolcano and the highest mountain on Java, Indonesia. The volcano regularly produces ash plumes and pyroclastic flows. Local hazards include ashfall, pyroclastic flows, lava flows, and lahars, which threaten nearby communities such as Lumajang, located about 25 km (16 miles) to the east. The region surrounding Semeru supports agriculture and residential settlements that are at risk from the volcano’s persistent explosive activity.