Mount Semeru, towering on the border of Lumajang and Malang Regencies in East Java, showed a significant increase in volcanic activity again on Sunday (June 28, 2026). The highest peak on Java Island recorded an eruption with an eruption column reaching a height of 1,000 meters above the summit, or 4,676 meters above sea level.
Mukdas Sofian, an officer at the Mount Semeru Observation Post, confirmed that the main eruption occurred precisely at 11:37 AM WIB. The ash column appeared thick, dominated by white to gray colors, moving slowly toward the southeast and south. According to seismograph records, this eruption had a maximum amplitude of 22 millimeters with an activity duration of 170 seconds.
As of now, Mount Semeru remains at Level III (Alert) status. Given the high potential danger, authorities have issued strict instructions for the public not to conduct any activities within a five-kilometer radius of the eruption center. This warning aims to minimize the risk of casualties from unpredictable volcanic activity.
In addition to the eruption threat, residents living along river basins originating from Semeru's peak, such as Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat, are urged to exercise extra caution. Residents are advised to continuously monitor developments, especially during severe weather or heavy rainfall at the summit, which could trigger pyroclastic flows or cold lava flows.
