While it hasn't had a major eruption in recent decades, it has shown signs of activity, including:

* Steam vents: These are common, indicating the presence of heat and volcanic gases.

* Minor eruptions: Ngauruhoe has had several minor eruptions in the 20th century, with the most recent being in 1975.

* Seismic activity: The area around Ngauruhoe experiences frequent earthquakes, indicating movement of magma beneath the surface.

Therefore, Mount Ngauruhoe is considered an active volcano and is constantly monitored by scientists.