Mount Semeru, located on the border of Lumajang and Malang Regencies, has once again shown an increase in volcanic activity. Throughout Wednesday (1/7/2026), the highest mountain on Java Island was recorded to have undergone four eruptions of varying intensity.
Based on data from the Mount Semeru Observation Post, the first eruption occurred in the early morning at 00:52 WIB, with an ash column height reaching 700 meters. Activity continued in the morning at 08:14 WIB, with an eruption column reaching a height of 800 meters. The peak of activity occurred at 09:24 WIB and 10:10 WIB, when the height of the white-to-gray volcanic ash column reached one kilometer above the summit.
To date, authorities confirm that Mount Semeru remains at Level III (Alert). The Chief Executive of BPBD Lumajang, Isnugroho, urged the public to increase vigilance and strictly adhere to all safe zone recommendations to avoid greater disaster risks.
The public is strictly prohibited from conducting any activities in the southeastern sector along the Besuk Kobokan riverbed up to a radius of 13 kilometers from the summit. Additionally, residents are advised to stay outside a five-kilometer radius from the crater to avoid incandescent material ejecta, and to remain aware of secondary hazards such as pyroclastic flows, lava falls, and lahar flows along river systems originating from the mountain.
