Volcanic ash from Lewotobi volcano observed at 3 700 m (12 100 feet) a.s.l., Indonesia

Volcanic ash from Lewotobi in Indonesia was observed at an altitude of 3 700 m (12 100 feet) above sea level at 06:20 UTC on October 9, 2025. The advisory was issued by the Darwin VAAC at 06:40 UTC.

The ash cloud was observed between the surface and 3 700 m (12 100 feet), based on reports from ground observations, Himawari-9 satellite imagery, and model data. The ash was reported moving southwest at a speed of 28 km/h (17 mph). The cloud was partially visible on current RGB satellite imagery due to meteorological cloud obscuration. The current Aviation Color Code is Red.

According to the Smithsonian / USGS Weekly Volcanic Activity Report for September 24–30, 2025, Lewotobi Laki-laki produced daily white-and-gray or gray ash plumes up to 2 000 m (6 600 feet) above the summit, drifting north, northwest, west, and southwest. Local airport disruptions due to ash led to several canceled flights, and the Alert Level was lowered to 3 (on a scale of 1–4) on September 29, with a 6 km (3.7 miles) exclusion zone around the volcano.

Lewotobi is a stratovolcano complex located in eastern Flores, Indonesia, consisting of Lewotobi Laki-laki and Lewotobi Perempuan cones. The primary hazards include ashfall, pyroclastic flows, and lava flows, with nearby settlements such as the town of Larantuka at risk from significant eruptions. The region is susceptible to disruption of air traffic and local agriculture due to ash emissions.