Indonesia's Merapi and Semeru Volcanoes Erupt in Mid‑July 2026

On July 12‑13 2026 Indonesia experienced heightened volcanic activity at two of its most active peaks.

Gunung Merapi emitted six hot‑gas and lava avalanches that traveled up to 2 km toward the Kali Boyong and Kali Krasak valleys. The Geological Agency kept the volcano at Level III (Alert) and warned residents to avoid the southern‑west and southeast hazard zones extending several kilometres from the crater.

Gunung Semeru erupted repeatedly throughout July 12, producing ash plumes that rose 800‑900 m above the summit and generated several seismic shocks. PVMBG also placed Semeru at Level III and advised the public to stay clear of the southeast sector along the Besuk Kobokan river, restricting activities within a 5‑km radius of the crater and up to 13 km from the eruption centre.

Both volcanoes remain closely monitored as magma supply continues, and authorities have urged communities to remain vigilant for ashfall, pyroclastic flows, and lahars.