Warning! Mount Semeru Erupts Again Tonight (Sunday, January 4, 2026)

Mount Semeru in East Java erupted again on Sunday (January 4, 2026) at 00:22 WIB. In the last week, Mount Semeru has erupted 30 times.

Based on eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the height of the ash column was observed to be approximately None meters above the peak (None meters above sea level).

The visual of the eruption was not observed. The eruption of Mount Semeru was still ongoing when this report was made.

(Read: Warning, Jakarta's Air Quality This Morning is the World's Worst (Thursday, June 15, 2023))

According to MAGMA Indonesia's volcano activity report, Mount Semeru's activity level is at Level III (Alert). Seismic observations on January 4, 2026, at 18:00-23:59 WIB showed 41 eruption earthquakes with amplitudes of 11-22 millimeters and earthquake durations of 76-110 seconds.

Then, 6 rockfall earthquakes with amplitudes of 4-6 mm and earthquake durations of 29-43 seconds, and 3 emission earthquakes with amplitudes of 3-7 millimeters and earthquake durations of 55-57 seconds occurred.

PVMBG advises against any activity in the southeast sector along Besuk Kobokan, as far as 13 kilometers from the peak (eruption center). Beyond that distance, the public should not engage in activities within 500 meters of the riverbank (river border) along Besuk Kobokan as it has the potential to be affected by the expansion of hot clouds and lava flows up to 17 kilometers from the peak.

Throughout 2026, MAGMA Indonesia has recorded 52 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most with 30 occurrences.

(Read: Jakarta's Air Quality is Bad, Losing to Other ASEAN Capitals)