Eruptions on White Island still remain a threat, according to GNS Science.
It says the risk at the volcano off the coast of Bay of Plenty is the greatest it has been since ash emissions and small eruptions began in August last year.
On Friday, scientists flew over the gas plume to gain a clearer picture of what is happening inside the volcano.
GNS volcanologist Brad Scott said it is still in a state of unrest, which means the risk of an eruption remains.
However, Mr Scott said activity on White Island has not got worse since December.
No further flights have been scheduled, but GNS will continue to monitor the volcano.
On Thursday, GNS upgraded its aviation alert to orange.