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

Volcanic ash from Semeru volcano in Indonesia was observed at an altitude of 4 300 m (14 100 feet) above sea level at 09:10 UTC on October 29, 2025. The advisory was issued by the Darwin VAAC at 09:30 UTC.

According to the VAAC advisory, the ash cloud was reported between the surface and flight level 140, which corresponds to approximately 4 300 m (14 100 feet) above sea level. The ash was reported moving west at approximately 9 km/h (5 mph). Satellite imagery from Himawari-8 could not identify the ash due to meteorological cloud cover, but ground observations confirmed ongoing intermittent discrete eruptions. The current Aviation Color Code is Orange.

The Global Volcanism Program reports that activity at Semeru continued with daily eruptive events during late September 2025. Ash plumes during that period rose 400–900 m (1 300–3 000 feet) above the summit and drifted in multiple directions. The Alert Level remained at 2, with a recommendation for the public to stay at least 3 km (1.9 miles) from the summit in all directions and up to 8 km (5 miles) from the summit to the southeast due to lahar, avalanche, and pyroclastic flow hazards.

Semeru is a stratovolcano located in East Java, Indonesia, and is the highest volcano on the island. Known hazards include ashfall, pyroclastic flows, and lahars, which can threaten nearby settlements such as the town of Lumajang. The volcano poses a significant risk within a radius of several kilometers (miles) due to its frequent eruptions and unstable slopes.