TEMPO.CO, Jakarta - Mount Semeru in Lumajang, East Java, erupted on November 19, 2025. The volcano reportedly ejected an ash column reaching approximately 2,000 meters above the peak. During the eruption, Mount Semeru emitted hot avalanche clouds that traveled up to seven kilometers from the summit, with thick ash columns observed moving toward the north and northwest.
Below, Tempo summarizes several key facts regarding the eruption of Mount Semeru.
1. Dozens of Climbers Trapped in Ranu Kumbolo
Several climbers were reported trapped in the Ranu Kumbolo area on Mount Semeru. Ranu Kumbolo is a crater lake located at an altitude of 2,400 meters above sea level, roughly a six-hour trek from the peak via the Kalimati climbing route.
Basarnas (National Search and Rescue Agency) noted that at least 60 climbers and 15 guides were stranded at Ranu Kumbolo due to foggy and rainy weather. However, the Basarnas Deputy of Operations and Preparedness, Edy Prakoso, stated that the climbers were safe.
"The condition in Ranu Kumbolo is safe, but there is an advisory to descend," he said.
He assured the public that his agency was ready to evacuate the climbers trapped on Mount Semeru. The evacuation is being carried out in coordination with joint teams from the National Disaster Mitigation Agency (BNPB), the Regional Disaster Mitigation Agency (BPBD), and the Indonesian Armed Forces and National Police (TNI-Polri), which were deployed shortly after the eruption.
2. Three Villages Affected
The National Disaster Mitigation Agency (BNPB) recorded that three villages in the Mount Semeru area of Lumajang, East Java, were affected by the eruption. The affected areas include Supit Urang and Oro-Oro Ombo villages in the Pronojiwo district, as well as Penanggal Village in the Candipuro district.
Volcanic activity at Mount Semeru rose from "Alert" (Level II) to "Standby" (Level III) on the afternoon of Wednesday, November 19, 2025. The head of the BNPB, Lieutenant General Suharyanto, stated that his agency was closely monitoring the increase in volcanic activity.
Suharyanto instructed his staff to respond immediately to the impact of the eruption, focusing on casualties, damage assessments, and evacuations. This response included establishing evacuation posts in several locations.
3. Hundreds of Residents Flee Following Eruption
A total of 957 residents sought refuge in safe zones following the eruption. Several evacuation points have been filled with affected residents since Wednesday night, November 19.
Data from the Lumajang District Disaster Mitigation Agency (BPBD) indicates that approximately 100 people are sheltering at the SD 04 Supiturang school building, around 500 people at the Ar-Rahmah Mosque, and about 200 people at SD Sumberurip 02. Some residents also took refuge at the Oro-oro Ombo Village Hall.
Meanwhile, in the Candipuro district, roughly 55 evacuees are staying at the residence of the Sumbermujur Village Head, and 101 people are at the Candipuro district office. These evacuees originated from Sumbersari Hamlet, Supiturang Village, and Pronojiwo District; others are currently seeking refuge at the Nurul Jadid Mosque and State Elementary School or SDN Supiturang 04.
Residents of Gunung Sawur Hamlet and Penanggal Village are currently sheltering at the Penanggal Village Office.
Lumajang Regent Indah Amperawati requested the activation of a command post to effectively handle the emergency. She stated that the local government had prepared suitable evacuation locations for residents. The local government will also declare a state of emergency response for one week, until November 26, 2025.
"The safety of residents is our top priority. This evacuation is carried out to protect every family, and the process has been designed to be safe and orderly," said Indah.
4. Ministry of Social Affairs Distributes Rp463 Million in Aid
The Ministry of Social Affairs dispatched logistical support to residents affected by the eruption on Wednesday, November 19, 2025. The central government sent aid valued at Rp463 million.
The assistance focuses on providing protection, temporary shelter, and food for vulnerable groups. The logistical aid includes blankets, mattresses, family and multipurpose tents, roll-up tents, family kits, kidware, 1,000 packs of ready-to-eat meals, and 480 children's meal packs.
In addition to logistical aid, the Ministry activated a field kitchen at the Sumberurip Village Hall in the Candipuro district with a production capacity of 1,300 servings per day. Food aid is distributed twice daily to all evacuees.
"The Ministry of Social Affairs ensures that all residents affected by the eruption of Mount Semeru receive the best protection, safe places, and basic needs without interruption," said Minister of Social Affairs Saifullah Yusuf (Gus Ipul) in a written statement.
Eka Yudha, Dinda Shabrina, and David Priyasidarta contributed to the report
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