Mount Semeru, standing majestically at 3,676 meters above sea level on the border of Lumajang and Malang Regencies, showed intense volcanic activity once again on Wednesday, July 1, 2026. According to records from the Mount Semeru Observation Post, the highest volcano on Java Island recorded four eruptions throughout the morning and early afternoon.
The intensity of the eruptions showed an upward trend since the first eruption occurred at 00:52 WIB with an ash column reaching a height of 700 meters. Activity continued at 08:14 WIB with a column height of 800 meters. Heading into the late morning, the eruptions grew stronger, with ash column heights reaching 1 kilometer during consecutive eruptions at 09:24 WIB and 10:10 WIB. The accompanying ash columns were observed ranging from white to gray with thick intensity.
Responding to this escalation, the Acting Head of the Lumajang Regional Disaster Management Agency (BPBD), Isnugroho, stated that there are currently no reports regarding the impact of volcanic ash fall in residential areas. Nevertheless, the public is urged to remain vigilant and adhere to established exclusion zone regulations as Mount Semeru's alert status remains at Level III (Alert).
The BPBD strictly prohibits residents from conducting activities within a five-kilometer radius of the summit, particularly due to the threat of incandescent rock projectiles. Additionally, the public is forbidden from approaching the area along Besuk Kobokan up to 13 kilometers from the eruption center and must maintain a distance of 500 meters from riverbanks due to potential threats of pyroclastic flows and lahar flows that could extend up to 17 kilometers.
Residents living along rivers originating from Semeru's summit, such as Besuk Bang, Besuk Kembar, and Besuk Sat, are advised to heighten vigilance regarding the potential for lava avalanches and cold lahar flows, especially during severe weather on the mountain slopes.
