The active vent temperature of Whakaari/White Island has fallen more than 300C in the past few weeks, an observation flight has found.
Data shows a substantial decrease in the vent temperature and a small decrease in gas output.
The state of moderate to heightened unrest continues and the volcanic alert level remains at level 2, a Geonet report said.
Last week, GNS Science researchers took flights around the volcano to collect visual observations, measure the levels of gas being emitted and the temperature of the active vent area.
The maximum vent temperature was 191C, a decline from 516C in December. During September-November, temperatures ranged from 202C to 264C. Temperatures over 500C were also recently observed in July and August.