The Philippine Institute of Volcanology and Seismology (PHIVOLCS), in coordination with the Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA), issued a lahar advisory on the evening of June 6, 2025, following significant rainfall in the vicinity of Kanlaon Volcano.
According to PAGASA Regional Weather Advisory No. 2, the Negros Island Region has been experiencing the effects of a Low Pressure Area (LPA) combined with the Southwest Monsoon. These weather systems have caused intense rainfall over the Kanlaon Volcano area, prompting concerns about volcanic sediment flows.
In particular, PAGASA’s Heavy Rainfall Warning No. 2 (#VISPRSD) noted moderate to heavy rain from late afternoon to early evening, which triggered lahars—volcanic mudflows—on the southern and southwestern slopes of Kanlaon. The Kanlaon Volcano Observatory in La Carlota City recorded 45.5 mm of rain in just 3.5 hours. However, rainfall totals are believed to be even higher near the summit.
Social media users and local officials reported cohesive, cement-like lahars flowing along Buhangin River and beneath Hacienda 92 Bridge in Barangay Sag-ang, as well as along Ibid Creek in Barangay Biak-na-bato, La Castellana, Negros Occidental.
The ongoing Southwest Monsoon season poses further risks, as it is expected to bring intermittent heavy rains in the coming weeks and months. These conditions could continue to generate lahars and muddy streamflows, especially in areas that have already been affected.
PHIVOLCS warns that communities located on the middle and lower slopes of southern Kanlaon are at risk of flooding, burial, or being washed out by future lahar events. Authorities are urging residents and local government units to stay vigilant, monitor weather advisories closely, and act promptly when heavy rainfall begins—often the only warning sign before lahars occur.
Pre-emptive evacuations and continuous monitoring are strongly recommended to prevent loss of life and property. PHIVOLCS emphasizes that preparedness and timely response are crucial during this period of heightened lahar threat.