WhereIsAtlas · Natural disaster

Mount Pinatubo Eruption (1991)

One of the largest volcanic eruptions of the 20th century — a blast heard across Southeast Asia

Concluded — Mount Pinatubo erupted catastrophically on 15 June 1991 in one of the largest volcanic eruptions of the 20th century, forcing huge evacuations and sending ash and lahar across the region.

Mount Pinatubo, a volcano in the Zambales mountains of the Philippines, had been dormant for centuries. In 1991, seismic activity and a growing plume of ash signaled that it was waking up. Scientists and officials — aware of the danger — mounted one of the largest volcanic evacuations in history.

On 15 June 1991, the volcano erupted climactically. The blast was enormous, among the largest volcanic eruptions of the 20th century. It ejected an immense column of ash high into the atmosphere, sent pyroclastic flows down the slopes, and blanketed the surrounding region in ash. The eruption coincided with a typhoon, creating a deadly mix of ash and rain that produced catastrophic lahar (volcanic mudflows) in the following months.

The scale of the disaster was immense, but the early evacuation saved tens of thousands of lives in the affected areas. The eruption also had a global effect: the sulfur dioxide it injected into the stratosphere briefly cooled the Earth's climate.

Quick facts

Date: June 15, 1991
Location: Mount Pinatubo, Zambales, Philippines
Scale: One of the largest eruptions of the 20th century
Early warning: Among the largest evacuations in history
Effects: Ash, pyroclastic flows, and later lahar
Global: Injected SO2 that briefly cooled the climate
Legacy: A landmark in volcano monitoring and early warning

Sources

Mount Pinatubo - Wikipedia — Wikipedia (2026-09-04)
1991 eruption of Mount Pinatubo - USGS — https://www.usgs.gov/volcanoes/mount-pinatubo