Strong winds and warm temperatures are making conditions difficult for firefighters battling a remote blaze in Otago.
One fire is moving through tussock towards the summit of Ben Lomond and smoke is visible from Queenstown.
The fire is expected to burn out once it reaches the snow line but helicopters are on standby.
Meanwhile, seven helicopters and five crews are working near Macraes, northwest of Dunedin after a burn-off grew out of control.
Fire and Emergency New Zealand (FENZ) says there are only power lines in the area but there's no risk to them at this stage.
People should not be attempting controlled burns in these conditions, a FENZ spokeswoman says.
"A small amount of heat in an old fire site can re-ignite and winds transport embers into [the] surrounding vegetation."
MetService Meteorologist Rob Kerr said strong wind watches are in place for Southland, Clutha, and the Canterbury High Country.
FENZ says warm days and wind in Otago have dried tussock, grasses, and other material making it easy to ignite.
"People need to be extra careful and think about what they are doing," the spokeswoman said.