It was the sunniest January ever for Auckland this year, with more than 308 sunshine hours logged, but the first week of February will be wetter than the whole of January for some parts of the North Island, forecasters say.

A humid northwesterly flow across the country would continue to bring heavier falls, especially in North Taranaki, Westland and Fiordland where rainfall warnings remain in force for Monday, MetService said.

January had been dry and warm for many parts of the country, setting numerous records.

In Auckland, more than 308 hours of sunshine were logged during January, making it the sunniest month on record.

Tauranga was also bathed in sunshine, with 327.5 hours recorded, just six minutes short of the sunniest month there since 1935.

Dunedin too observed its sunniest January, and Hamilton its fourth sunniest.

Cloudier skies and spells of rain would set the theme for the North Island today, while in the South Island thunderstorms were again a threat for parts of Southland and Otago, MetService said.

For Canterbury and eastern Marlborough, the dry weather would hold on for another day and temperatures were set to rise into the high twenties for many spots east of the Southern Alps.

A brighter day could be expected across the North Island tomorrow, and high temperatures were forecast to returning for Hawkes Bay and Gisborne.

Meanwhile, a cooler southwesterly change would spread northwards across the South Island, bringing a scattering of showers and cooler temperatures.

Temperatures in Christchurch were expected to drop from 30C today to a much cooler 21C tomorrow.

The south westerly change would continue to move across the country for the rest of the week and would result in a cooler and showery Waitangi Day, MetService said.

The showers were forecast to ease through the weekend.

Beyond this week. temperatures would most likely be in the "above normal" range for all regions of the country until April, according to a climate outlook released by the National Institute of Water and Atmosphere (Niwa) last week.

The dry conditions continued as sea surface temperatures across the equatorial Pacific Ocean were borderline between neutral and weak El Nino conditions.

"However - as was the case over the past few months - the atmospheric circulation in the Pacifc is still inconsistent with El Nino," the report said.

International guidance indicated that the probability of El Nino conditions developing over the next three months was about 60 per cent.

Over that period, higher pressures than normal were forecast over and to the southeast of the country, and slightly lower than normal pressures were likely to the north of New Zealand.

"This atmospheric pressure pattern is expected to be associated with weak easterly flow anomalies."

Sea surface temperatures around New Zealand were forecast to be in the above normal range all around the country.

In Northland, Auckland, Waikato and Bay of Plenty, temperatures were most likely to be above average, with rainfall in the near normal range, and soil moisture and river flow levels equally likely to be in the near or below normal.

Nationally, rainfall would be near normal in the north of the North Island and the north and west of the South Island, while rainfall totals for the season as a whole were equally likely to be in the near-normal or below normal in the east of the South Island.

In the east and west of the North Island, the coming season's rainfall was about equally likely to be near or above normal, Niwa said.

Soil moisture levels would most likely be below normal in the east of the South Island and about equally likely to be near-normal or below normal in all regions of the North Island and the west of the South Island.

River flows were most likely to be below normal in the east of the South Island and about equally likely to be near or below normal in the north and west of the North Island and the west of the South Island.

Near normal river flows were likely in the east of the North Island and the north of the South Island.

(Source NZME, Brendon Manning Jamie Morton)