Mount Semeru Erupts in Indonesia, Prompting Evacuations
Mount Semeru, one of Indonesia’s most active volcanoes, erupted early Friday, blanketing nearby villages in ash and prompting authorities to urge residents to stay vigilant. The eruptions, which began at local time ( Friday), sent hot clouds traveling southeast toward the Besuk Kobokan river area, according to reports from the Semeru Observation Post.
A thick column of volcanic ash rose (6,561 feet) above the summit, drifting north and northeast. A second eruption followed at , producing an ash plume reaching above the peak. Seismic monitoring recorded significant volcanic tremors during both events.
Authorities have raised the alert level for Semeru to Level III, Indonesia’s second-highest warning level. The Center for Volcanology and Geological Hazard Mitigation is advising residents and visitors to avoid all activities within (8 miles) of the crater in the southeast sector, particularly along the Besuk Kobokan river.
Warnings have also been issued against approaching riverbanks within , due to the risk of lava flows and expanding hot clouds that could extend up to from the summit. More than residents in the three villages most at risk in the district of Lumajang have been evacuated to government shelters, according to the National Disaster Mitigation Agency’s spokesperson, Abdul Muhari.
Mount Semeru is located along the border of Lumajang and Malang regencies in East Java province. The volcano unleashed searing clouds of hot ash and a mixture of rock, lava and gas that traveled up to (4.3 miles) down its slopes several times from midday to dusk on Wednesday, November 19, 2025, according to Indonesia’s Geology Agency.
Indonesia is situated on the Pacific “Ring of Fire,” a region known for frequent seismic activity, and is home to more than active volcanoes. No casualties have been reported as a result of the recent eruptions, and no immediate reports of major damage have surfaced.
Earlier reports indicated that Mount Semeru erupted five times, with ash rising above the peak. The current activity follows a significant eruption on Wednesday, November 19, 2025, which also triggered evacuations and prompted authorities to raise the alert level to its highest point.
