Mount Tongariro was quiet again overnight. Scientists monitoring the volcano say conditions are likely to be too cloudy on Friday for a flight to monitor gas levels.
GNS vulcanologist Nico Fournier said scientists were hoping to circle the volcanic gas plume to measure sulphur dioxide and carbon dioxide levels being ejected from the crater, following Wednesday's eruption.
However, a thunder storm has left too much cloud over the area .
"What we want to know is how much gas is coming out of the volcano and to do that we circle around the gas plume and we make some measurements from an aircraft equipped with some sensors," he said.
"We need the plume to go essentially out from the volcano so we can circle it and go under and above it.
The other thing we need is a good view and ... today's not looking essentially promising."
Dr Fournier said the volcano had been remarkably quiet overnight, but that doesn't mean it's calming down.
"The volcano can pretty much erupt at any time. The last eruption was only a few days ago so it's still pretty unstable, and it can occur with little or no warning at all."
He said Mount Ruapehu had also been quiet but there was still a slightly elevated risk.
Mount Tongariro erupted for about five minutes at about 1.30pm on Wednesday. It last erupted at 11.50pm on 6 August, for the first time since 1896-97.
