By tomorrow, however, a warmer airflow is forecast to move in and will push this colder air further east of New Zealand.
"By [tomorrow] night, many places will be milder than they will be tonight."
Aucklanders can expect fine spells and a few showers today. Strong southwesterly winds are also on the cards, but are expected to ease by this afternoon.
A high of 15C is forecast for the City of Sails and an overnight low of 8C.
Similar conditions are expected in northern parts of the North Island; while people in Gisborne are in for a mainly fine day with a chance of afternoon showers. A high of 14C is forecast there.
There will be cloudy periods and a few mornings showers in Wellington with southerly winds dying out by tonight. A high of 10C and overnight low of 5C are forecast for the capital city.
Some cloud and the odd shower are forecast for western parts of the North Island - with the odd shower about Wairarapa moving into Hawke's Bay around midday, as southwesterlies freshen.
Weather Watch analyst Aaron Wilkinson said those in South Westland can expect mostly sunny conditions today; while those getting showers on the West Coast will be happy to know those will gradually clear this afternoon.
"Marlborough is mostly cloudy, [with a ] risk of a shower or two.
"Nelson has some morning sun then cloud develops in the afternoon. Canterbury has a mostly sunny day, cloud about North Canterbury clears," Wilkinson said.
"Southland and Otago have the odd shower, snow flurries to low levels in the morning then gradually lifting. Any accumulations of snow will be very minimal to non-existent."
MetService says a few showers are forecast for Northland to Manawatu - including Coromandel Peninsula, Bay of Plenty and the central high country.
Wellington, Horowhenua, Kapiti and coastal Marlborough are all in for a brief period of showers spreading northwards this morning and afternoon; but otherwise, fine.
The remainder of Marlborough and Nelson is in for fine conditions apart from isolated afternoon and evening showers.
In Buller and Westland, the weather is fine apart from a few showers this morning just north of Harihari.
South of the country, in the Chatham Islands, showers - possibly sleety - are forecast this morning. However, they are expected to ease by this afternoon.
A number of marine warnings were issued late last night by MetService.
A strong wind advisory is in place for the Manukau Harbour and Waitemata Harbour as well as for the Hauraki Gulf and the area from Bream Head to Cape Colville.
SEVERE WEATHER OUTLOOK:
Meanwhile, a severe weather outlook shows there is moderate confidence of heavy rain and possibly heavy snow for the South Island on Friday and Saturday, according to MetService.
"[Tomorrow] an active front is expected to approach the lower South Island, then move across the South Island on Friday.
"Moist northwesterlies ahead of the front are forecast to bring rain to western parts of the South Island - and there is moderate confidence that rainfall accumulations will meet warning criteria in Fiordland and Westland on Friday."
By Saturday, much colder air is forecast to spread up the eastern parts of the South Island, while moist air heading down from the northwest could bring snow to quite low levels, MetService said.
However, at this stage, there is low confidence of significant widespread snowfall meeting warning criteria from Southland to Canterbury.
