Volcanic ash from Klyuchevskoy volcano observed at 7 000 m (23 000 feet) a.s.l., Russia

Volcanic ash from Klyuchevskoy in Russia was observed at 7 000 m (23 000 feet) above sea level at 05:20 UTC on October 13, 2025. The advisory was issued by the Tokyo VAAC at 06:00 UTC on the same day.

According to the VAAC advisory, ash cloud emissions were continuing from Klyuchevskoy. The ash was observed between the surface and flight level 230 (approximately 7 000 m or 23 000 feet). Some portions of the ash cloud were obscured by meteorological clouds. No Aviation Color Code was stated in this advisory. Forecasts predicted the ash could reach up to flight level 240 (about 7 300 m or 24 000 feet) in the subsequent 6 to 18 hours.

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

Klyuchevskoy is a stratovolcano located on the Kamchatka Peninsula, Russia, and is the highest active volcano in Eurasia. Hazards associated with Klyuchevskoy include ashfall, pyroclastic flows, and lava flows. The nearest populated areas potentially at risk include the towns of Klyuchi and Kozyrevsk, both situated within 50 km (31 miles) of the volcano.