Klyuchevskoy Volcano Ash Plume Reaches 18,000 ft (5,500 m) as of August 21, 20:00 UTC

A volcanic ash advisory was issued for Klyuchevskoy volcano in Kamchatka, Russia, reporting an ash plume rising to 18,000 feet (5,500 meters) as of August 21, 2026, at 20:00 UTC. This followed an earlier advisory the same day, at 08:00 UTC, which recorded the plume at the same altitude of 18,000 feet.

The advisory is part of a series issued over recent days. On August 19, plumes reached 23,000 feet (7,000 m) at both 05:20 UTC and 17:20 UTC. On August 18, an ash plume peaked at 27,000 feet (8,200 m) at 17:20 UTC, while an earlier advisory that day recorded 16,000 feet (4,900 m). On August 17, plumes reached 25,000 feet (7,600 m) at 09:00 UTC and 22,000 feet (6,700 m) at 17:20 UTC.

Klyuchevskoy stands at 4,835 meters and is Kamchatka's highest and most active volcano. The current eruption phase, involving summit fountaining and ash emission, began around August 16, 2026.

Volcanic ash advisories of this kind are issued repeatedly as an eruption evolves, with plume height changing from one reading to the next rather than settling at a fixed level. Klyuchevskoy's readings have moved between 16,000 feet and 27,000 feet across less than a week, which is the pattern that keeps this advisory active rather than closed.

For aircraft transiting Kamchatka airspace, ash plume height and drift direction determine which flight levels and routes remain usable at any given time, since ash ingestion risk to engines is altitude-dependent. Operators and dispatchers with routes near the region rely on successive advisories, not a single reading, to plan around the ash cloud.

The next advisory update, and whether plume heights continue trending down from the August 18 peak of 27,000 feet toward the more recent 18,000-foot readings, will indicate whether the eruption's ash-emission phase is easing or could intensify again.