From Orr and others, 2024: "Intermittent explosive eruptions have taken place [at Cleveland] every year since 2001. In 2020, Mount Cleveland had one confirmed explosion...
"[O]n June 2 at 06:31 UTC (June 1 at 21:31 HADT), a small explosion triggered the infrasound alarm in Adak, Alaska, and was detected shortly thereafter on the infrasound array in the City of Dillingham, Alaska. A small ash cloud was observed shortly afterward in satellite imagery drifting southward at an altitude of ~22,000 ft (~6,700 m). This event was the first explosion detected at Mount Cleveland since January 2019 - a span of 17 months and the longest repose period at the volcano since its onset of eruptive activity in 2001. In response, the Aviation Color Code and Volcano Alert Level were elevated to ORANGE and WATCH on June 2 at 07:46 UTC (June 1 at 22:46 HADT).
"The explosion destroyed ~60 percent of the 2019 dome, excavated and widened the crater slightly, and sent pyroclastic and debris flows as far as ~3 km [1.9 mi] down the flanks of the volcano. Hot debris landing on snow may have triggered some of these flows by melting and remobilizing mixtures of debris and snow. Satellite imagery acquired after the explosion also showed a trace ash deposit extending southward from the summit, discoloring the snow on the volcano’s flanks. Aerial photographs taken on June 3 showed that impact craters from ballistically ejected bombs and blocks dotted the snow, and satellite imagery acquired later showed that the ejecta reached as far as 1,400 m [4,600 ft] from the summit crater.
"Activity at Mount Cleveland diminished after the June 2 explosion. A weak steam plume dissipated after a few days, and no conspicuous degassing or definitive elevated surface temperatures were observed in satellite imagery thereafter through the rest of the year. Because of the lack of activity, the Aviation Color Code and Volcano Alert Level were downgraded to YELLOW and ADVISORY on June 17, then to UNASSIGNED on September 3, where the volcano stayed for the rest of the year."