New Zealand weather: Christmas Day to be showery in some parts as others get sun, heat

Christmas Day will be unseasonably cool for some parts of New Zealand and sunny and hot for others, as Mother Nature dishes up a mixed set of conditions on December 25.

If you're spending the day high enough in the Southern Alps, you may even get a fabled white Christmas as nearby Dunedin, Queenstown and Invercargill all limp to double-figure highs.

Canterbury and the West Coast are also likely to be cool, Weather Watch says, with highs in the low to mid-teens, while the western coast of the North Island will also be colder than usual for this time of year.

The South Island will also be beset by showers - some light on the coast and others heavy in inland areas. The chilly and wet conditions down south are caused by the combination of a low and a front moving up the country from the south.

Luckily for most of the North Island, the front won't reach them until after Christmas Day.

While the west will get cloud, eastern parts of the island will enjoy balmy temperatures and mainly sunny skies on the 25th. Hawke's Bay is forecasted to peak in the mid-20s, and inland parts of Gisborne and the Bay of Plenty are set to bake in the late-20s.

The rest of the North Island is likely to reach the low-20s alongside Nelson and Marlborough, which, at the top of the South Island, are jammed right between the high and the low moving up the country.

Taranaki, Auckland and the Bay of Plenty, while not chilly, will get some wind. It'll only be a 30km/h sou'wester, however, and will blow intermittently.

Meanwhile cloudy skies will cover most of the South Island, the western North Island and Auckland.

It'll be a relief for most Kiwis that Cyclone Yasa, which has loomed as a threat to our shores for well over a week, will fail to reach New Zealand.

Weather Watch says this means long-range forecasts suggesting normal rainfall would return mid to late-December could now be wrong.

"Auckland, along with Waikato, Bay of Plenty, Coromandel Peninsula and Northland may all be looking at a much drier than usual December despite La Nina being here," the forecaster said.

"We've been saying for months now that this La Nina in particular looked moderate and short-lived, meaning it may not have the oomph to really bring in the rain to New Zealand - that it was a silver lining for dry regions, but not the silver bullet to fix it."