NZ weather: Wet week ahead with three waves of rain expected for New Zealand

Bad news for people hoping to dust off the skis this school holidays as the country is in for a week of rain and higher temperatures.

NIWA has released its predictions for the rest of winter and it looks like we are in for a warm, wet period.

NIWA principal scientist and forecaster Chris Brandolino told Ryan Bridge on AM there are going to be multiple waves of rain this week.

He said the first wave, or "round one", will bring rain to the North Island on Tuesday afternoon and Wednesday.

"There will be some pockets of heavy rain, but I don't think this particular round of rain will bring any widespread issues," Brandolino said.

He said the country will catch a break from Wednesday afternoon until Thursday night when the next round of rain comes.

The second wave of rain is expected to hit the country from Thursday night to Friday night.

"That will be from a pretty beefy low. That will bring more widespread rain, probably pretty good wind as well, maybe some thunderstorms," Brandolino said.

He said the third wave of rain is expected later in the weekend.

"It's really the cumulative effects of not one, not two, but probably three weather events," Brandolino said.

He said if there are going to be any issues with flooding it will be around the second and third waves as the rain accumulates.

But with that rain comes warmth.

NIWA's seasonal climate outlook for the rest of winter expects temperatures to be warmer than average across all of the country.

Brandolino said this is mainly due to La Nina, which is a weather pattern that occurs in the Pacific Ocean.

La Nina tends to bring warmer temperatures with more north–easterly winds. The North Island can expect more moist, rainy conditions, while there is likely to be reduced rainfall to the south and southwest of the South Island.

Brandolino said the rising ocean temperatures are also behind the warmer winter.

"We are an island nation, our air temperatures and our seas temperatures are pretty closely linked. So if our ocean temperatures are running warmer than average, it's going to be hard to get sustained cold snaps."

Brandolino said there have been dozens of locations across the country that saw record warm temperatures in June and that is expected to be similar in July.

"If you are a cold weather fan, unfortunately, probably not going to see a lot of cold weather for the rest of winter and spring. Yes, cold snaps, but that doesn't define the season."