Volcanic activity at White Island is the most vigourous it has been in years and there is a 50-50 chance the North Island volcano may soon erupt, according to GNS Science.
The volcano in the eastern Bay of Plenty is always in a state of unrest, but in the past three weeks volcanic activity has been stronger.
GNS volcanologist Brad Scott visited the island on Monday and says the hydrothermal activity is some of the most active he has seen there for many years.
Mr Scott says this level of hydrothermal activity usually leads to stronger volcanic activity.
However, he says it is not clear which way the volcano is going to go, and people visiting the island should be aware of the risk.