Volcanic ash from Lewotobi volcano observed at 6 700 m (22 000 feet) a.s.l., Indonesia

Volcanic ash from Lewotobi in Indonesia was observed at an altitude of 6 700 m (22 000 feet) above sea level at 15:00 UTC on October 15, 2025. The advisory was issued by the Darwin VAAC at 15:20 UTC on the same date.

According to the advisory, the ash cloud was detected between the surface and 6 700 m (22 000 feet) and was moving northwest from the summit. Satellite imagery from Himawari-8 confirmed the observation. The current Aviation Color Code is Red. Forecasts indicated the ash would dissipate within 12 hours, with the ash cloud expected to remain between the surface and 6 700 m (22 000 feet).

The Global Volcanism Program reported that, during September 23–29, 2025, Lewotobi Laki-laki produced daily white-and-gray or gray ash plumes reaching up to 2 000 m (6 600 feet) above the summit, which drifted in multiple directions. Increased activity previously led to airport closures and flight cancellations in the region, and on September 29, the Alert Level was reduced to 3, with a 6 km (3.7 miles) exclusion zone from the summit advised.

Lewotobi consists of twin stratovolcanoes known as Lewotobi Laki-laki (male) and Lewotobi Perempuan (female). Both volcanoes are capable of explosive eruptions that can generate ashfall, pyroclastic flows, and lava flows. The region is sparsely populated, though several villages and the town of Larantuka, located about 60 km (37 miles) west, could be affected during major eruptions. Ashfall and lahars are among the principal hazards posed by eruptions at Lewotobi.