High temperatures and increased seismic activity have been recorded at Mt Ruapehu's Crater Lake.
The lake usually cycles between 15degC and 45degC, but over the past six months, it has remained at around 30degC. Over the last two weeks, the lake temperature has raised 0.5degC per day.
- Minor volcanic unrest at Mt Ruapehu, lake temperature rising
- 'Volcanic tremors' detected beneath Mt Ruapehu
Alongside this rise in temperature, seismic activity has increased. However, the tremors are moderate - far below what a human could feel.
On Tuesday, the lake reached 42degC. As the lake heated up, tremors have increased.
When it reaches 45degC, there's an increased risk of eruption. However, in 2016, the lake reached 46degC with no eruption.
GNS Science will continue to monitor the lake, as they have since 2009.
The Volcanic Alert Level is still at level one, so scientists say we don't have to worry yet.