New Year's Eve weather: Outlook good for summer-starved Kiwis

New year, new weather.

After a month of spring-like weather which saw serious flooding in the South Island, thunderstorms and tornadoes in the north, and a far from spectacular summer Christmas everywhere, relief is on the way.

A dreary final few days should clear for most parts of the country for fine and warm New Year's Eve celebrations across much of New Zealand.

The last day of 2019 would start cloudy across both islands, MetService meteorologist Nicole Ranger said.

But the gloom wouldn't last.

"It'll fine up quite nicely."

New Year's Eve weather forecasters have good news for revellers. Photo / Paul Taylor

The South Island would be generally dry, with only Fiordland a possibility for rain late in the day.

In the North Island only eastern areas around Gisborne and Hawke's Bay were at risk of showers, everywhere else should be fine.

Models also indicated some northerlies could push into Wellington during the evening of New Year's Eve, but wind shouldn't be a problem elsewhere.

And a warm day was on the way for some South Island spots - New Year's Eve highs could reach 30C in Alexandra, 27C in Wanaka and 26C in Queenstown.

North Island holiday spots would also sizzle under warm temperatures, with the Bay of Islands, Coromandel and Taupō likely to reach the mid-20s.

Main centres would be dry but a mixed bag temperature-wise. Auckland could expect 23C on New Year's Eve, Hamilton and Tauranga 25C, Christchurch 22C and Dunedin 24C.

Meanwhile, Kiwis would have to endure a few more days - including some chilly ones - of spring-like weather until more summery conditions arrive with the new year.

An unsettled Christmas week will culminate in a cold front spreading north on Saturday , with showers across the North Island in the morning, MetService meteorologist Andy Best said.

Australia is in the thick of a devastating bush fire season. Photo / AP

In the South Island most places could expect a showery Saturday, except the top of the island.

The front also means much cooler weather for many. Single-digit lows are expected in several places overnight Saturday - Hamilton and Blenheim will drop to 7C, and Alexandra and Masterton to a chilly 5C.

Tomorrow , the month's fickle weather should continue, with isolated showers in central North Island areas but fine conditions elsewhere. Showers would turn to rain west of the main divide in the South Island, with heavy falls possible.

The rest of the South Island would be mainly fine, although rain was expected at times from eastern Otago south, Best said.

"We're in very unsettled, almost spring-like conditions. We're seeing endless fronts coming across the Southern Ocean."

Australia is in the thick of a devastating bush fire season. Photo / AP

The current pattern was thanks to a large ridge of high pressure trapped over Australia, which has been baking under record-breaking high temperatures and where a raging bush fire season had killed at least nine and destroyed hundreds of homes.

The high was blocking southerlies from coming on to Australia, which were then being redirected to our shores, Best said.

"[The southerlies] want to push into Australia, but they're only hitting Victoria and Tasmania, and then strong westerlies are bringing them across to New Zealand."