Warning! Mount Semeru Erupts Again Tonight (Wednesday, December 31, 2025)

Mount Semeru in East Java erupted again on Wednesday (12/31/2025) at 00:04 AM Western Indonesian Time (WIB). In the last week, Mount Semeru has erupted 74 times.

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

Visual eruption was not observed. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 150 seconds.

(Read: West Kalimantan Has the Worst Air Quality in Indonesia This Morning (Friday, August 18, 2023))

According to MAGMA Indonesia's volcano activity report, Mount Semeru's activity level is at Level III (Alert). Seismic observations on December 31, 2025, at 18:00-23:59 WIB showed 36 eruption/explosion earthquakes with an amplitude of 10-22 millimeters and a duration of 79-160 seconds.

Followed by 1 exhalation earthquake with an amplitude of 4 millimeters and a duration of 43 seconds, and 2 distant tectonic earthquakes with an amplitude of 15-35 millimeters s-p 13-14 seconds and a duration of 46-52 seconds.

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 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 2025, MAGMA Indonesia has recorded 7,559 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions with 3,147 events.

(Read: Indonesia's Air Quality Worst in ASEAN in 2022)