After the disruption, travellers should contact their airline or check the airport's website -www.aucklandairport.co.nz/flights - for more information.
Parts of Auckland were blanketed by fog this morning, but the airport was initially unaffected.
However, fog rolled in to the airport at 7.36am, the spokesman said.
Much of the country awoke to a clear, crisp morning, with a sparkly layer of frost as far north as Auckland.
Temperatures fell below zero in Auckland around dawn this morning, with Ardmore Airport the city's coldest spot.
The temperature dipped to -0.9C between 7am and 8am, the same recorded on Wednesday this week, making it the coldest equal low this year.
Whenuapai was a smidgeon warmer on -0.8C while Auckland Airport reached 1.1C.
It was also a chilly start in other main centres, with -2.1C in Hamilton, -3.5C in Christchurch, -3.2C in Dunedin and -3.8C in Queenstown. Wellington was a comparatively mild 4.1C.
Coldest across the country was Waiouru, with -7.3C, just ahead of St Arnaud's -7.2C.
Pukaki, near Mt Cook, dipped to -6.4C and Raetihi started the day on -5.1C. In Taupo's the overnight low fell to -4.9C.
Frosts can begin to occur when the temperature drops to around 2C or below, so many parts of the country could be affected this morning.
Queenstown and Alexandra shared a low of -3C, while at the other end of the island Blenheim nudged -1.7C.
MetService meteorologist Josh Griffin said it was a cold night, but not unexpected.
"It's nothing that outside the climatological norms."
Clear skies across much of the country meant chilled Kiwis would be rewarded with a nice day, barring a few isolated showers on the Taranaki coast.
Aucklanders can expect a high of 14C and Hamilton, Wellington and Dunedin residents 12C. It will be 11C in Christchurch.
The South Island's West Coast could also expect showers, turning to rain later today, as a south-westerly front began to move across the country, eventually crossing the North Island tomorrow, Griffin said.
A heavy rain watch has been issued for the ranges of Westland, south of Otira, and Fiordland, north of Doubful Sound, on Sunday.
Rain would also spread to most of the North Island tomorrow and through into Monday, he said.
But there's sunshine on the horizon - a ridge due after Monday is expected to bring settled weather to the country early next week.
