Warning! Mount Semeru Erupts Again Tonight (Saturday, January 3, 2026)

Mount Semeru in East Java erupted again on Saturday (1/3/2026) at 00:51 AM Western Indonesian Time. In the last week, Mount Semeru has erupted 20 times.

Based on eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the observed ash column height reached 1,000 meters above the peak or 4,676 meters above sea level.

The observed ash column was white to gray with moderate intensity towards the north. The eruption of Mount Semeru was still ongoing when this report was made.

(Read: Indonesia Has the Most Active Volcanoes in the World)

According to MAGMA Indonesia's volcano activity report, Mount Semeru's activity level is at Level III (Alert). Seismicity observations on January 3, 2026, from 18:00-23:59 Western Indonesian Time, showed 32 eruption earthquakes with amplitudes of 11-22 millimeters and earthquake durations of 52-137 seconds.

Subsequently, there were 5 avalanche earthquakes with amplitudes of 4-7 mm and earthquake durations of 35-40 seconds, and 1 exhalation earthquake with an amplitude of 8 millimeters and an earthquake duration of 60 seconds.

PVMBG advises against any activity in the southeast sector along Besuk Kobokan, as far as 13 kilometers from the peak (eruption center). Beyond this distance, the public is advised not to conduct activities within 500 meters from the riverbanks along Besuk Kobokan, as there is a potential for expansion of hot clouds and lava flows up to 17 kilometers from the peak.

Throughout 2026, MAGMA Indonesia has recorded 32 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most with 20 occurrences.

(Read: Volcanic Eruption Trends in Recent Years)