"It's looking like a pretty unsettled week," said MetService meteorologist Claire Flynn.
She said a weak front would produce scattered rain and drizzle in much of the North Island today, except in the Bay of Islands, where Paihia and Kerikeri are forecast to be sunny and dry, with daytime highs of 29C.
Today is expected to be a good beach day in the Bay of Islands. Photo / file.
In the South Island, a southerly change is expected to move up the east coast, bringing showers and cooler temperatures than yesterday's national high of 34.3C in Kaikoura.
Tomorrowa broad area of low pressure is forecast to move across the country, bringing scattered rain to the North and South islands, briefly heavy in Westland.
A front on Wednesday will bring showers to most places.
Flynn predicted Thursday will be the week's nicest day as a ridge of high pressure takes over briefly. Most of the country will be mostly fine, with just the odd isolated afternoon shower.
Friday brings another front with rain or showers for the South Island although mostly fine weather will hang on in the North Island.
The National Institute of Water and Atmospheric Research - Niwa - will this week publish its three-monthly climate outlook, covering the period to the end of March.
In its last outlook, published on December 1 and covering the period to the end of February, it said: "Typical summer conditions are expected of anticyclones crossing the North Island and prevailing westerly winds over the South Island."
Niwa's principal scientist, forecasting, Chris Brandolino, said yesterday the outlook for the next 10 days was "changeable" - some fine spells and some episodes of unusually cool weather that may last for several days.
"I think there will be some cool snaps, at least for the first week or two of January, blended with some settled periods.
"We had a hot summer last summer, particularly from January through March. Whether that happens this summer we will have to wait and see."
