Volcanic ash from Klyuchevskoy volcano observed at 8 200 m (27 000 feet) a.s.l., Russia

Volcanic ash from Klyuchevskoy in Russia was observed at 8 200 m (27 000 feet) above sea level at 05:20 UTC on October 15, 2025. The advisory was issued by Tokyo VAAC at 06:00 UTC on October 15, 2025.

According to the VAAC advisory, ash clouds were observed up to flight level 270 (approximately 8 200 m or 27 000 feet). The ash was moving west at 37 km/h (23 mph) according to satellite data from Himawari-8. Parts of the ash cloud were obscured by meteorological clouds. No Aviation Color Code was stated in this advisory.

The most recent Smithsonian / USGS Weekly Volcanic Activity Report noted that, as of late September 2025, wind was no longer resuspending ash previously deposited on the north flank of Klyuchevskoy and only fumarolic emissions were observed. The Aviation Color Code was lowered to Green on September 25, 2025.

Klyuchevskoy is a stratovolcano located on Russia’s Kamchatka Peninsula. It is the highest active volcano in Eurasia. Hazards include ashfall, pyroclastic flows, and lava flows. The nearby town of Klyuchi, located 30 km (19 miles) northeast of the volcano, is the principal population center at risk from volcanic activity.