Mount Semeru, located in East Java, has once again shown an increase in volcanic activity early Monday morning (29/6/2026). Based on reports from the local observation post, the highest mountain on the island of Java was recorded to have erupted six times, accompanied by white to gray ash columns reaching a height of 1,100 meters to the east and northeast.
One of the visually observed impacts was the flow of incandescent lava directed towards the southeastern sector heading to the Besuk Kobokan area. Mount Semeru Observation Post officer, Sigit Rian Alfian, confirmed that the flow distance of the incandescent lava reached 1,300 meters from the active crater.
In response to this phenomenon, relevant authorities issued a strict warning to the public to refrain from any activities within a 13-kilometer radius from the mountain peak. This distance is designated as a safe zone to avoid the danger of ejected incandescent materials or hot clouds.
In addition to the warning regarding the safe radius, communities near river basins originating from Mount Semeru are urged to increase vigilance against the potential for cold lava mudflows (lahars). Fluctuating weather conditions and volcanic dynamics require residents to always monitor official information from authorities for mutual safety.
