Mount Semeru Erupts with Pyroclastic Flow Today

Mount Semeru erupted again today, 19 June 2026. The volcano, situated on the border of Lumajang and Malang Regencies in East Java, also released a pyroclastic flow with a runout distance of 4.5 kilometres.

"Mount Semeru erupted on Friday at 07:21 WIB with an observed eruption column height of approximately 1,000 metres above the peak, or 4,676 metres above sea level," explained Mukdas Sofian, an officer at the Mount Semeru Observation Post in Lumajang.

The ash column was observed to be white to grey with thick intensity, leaning towards the north and northwest. The eruption was recorded on a seismogram with a maximum amplitude of 22 mm and a duration of approximately 5 minutes and 33 seconds.

Mount Semeru, the highest volcano on Java Island, has experienced six eruptions with column heights ranging from 700 metres to 1,000 metres above the peak.

Mukdas stated that the volcanic activity of Mount Semeru is currently at Level III, or Alert status, with a recommendation that the public not conduct any activities in the southeastern sector along Besuk Kobokan, up to 13 km from the summit.

"Beyond that distance, the public must also not conduct activities within 500 metres of the riverbank along Besuk Kobokan, as there is potential to be affected by the expansion of hot clouds and lava flows up to a distance of 17 km from the summit," he stressed.

He also emphasised that the public may not conduct activities within a 5 km radius of the crater or summit of Mount Semeru due to the danger of rock projectiles and the potential for hot clouds, lava avalanches, and lahars along the river or valley streams originating at the summit. These streams include Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat, as well as the potential for lahars in small rivers that are tributaries of Besuk Kobokan.