Temperatures are expected to reach double digits in Dunedin today, a far cry from yesterday when the mercury in the central city reached just 2.8degC.
Queenstown recorded just 0.3 degrees.
Snow showers, which left much of the South blanketed yesterday, were expected to ease last night.
Today is forecast to be mainly dry in the region after a frosty start, apart from showers in Clutha.
Up to 15cm of snow fell in Dunedin hill suburbs yesterday, making driving treacherous in places and prompting an advisory notice from police for motorists.
Senior Sergeant Steve Aitken said roads were expected to freeze and "could be treacherous" for motorists.
WeatherWatch forecaster Philip Duncan changed Auckland's forecast late last night to include the possibility of snow flurries atop the Waitakeres.
"We've got the right conditions to possibly be seeing a few very light snow flurries," he said.
"That's how cold it is - we don't see the word 'snow' in the Auckland forecast very often."
Further south, motorists were being warned to stay wary of road conditions and black ice as temperatures were not likely to creep up until close to noon after yesterday's snow, sleet, hail, gales and heavy rain.
MetService duty forecaster Mike O'Connor said the last of the snow flurries would clear this morning, making way for warmer, calmer weather for the rest of the week.
Yesterday some Dunedin schools were closed and bus services cancelled because of to snow, and mail deliveries halted in most of Otago.
Heavy snow fell in Central Otago, and areas of Canterbury and Wellington got light snowfall and cold southerly winds with hail and sleet.
The Rimutaka Hill Rd between Wellington and Wairarapa was closed intermittently. Up to 20 vehicles were stuck on it after its first closure at 9am. The road had closed again last night.
Heavy snow in the central North Island closed the Desert Road between Rangipo and Taihape yesterday afternoon, and the Transport Agency could not say when it would re-open.
What was believed to be a tornado struck in Port Waikato, tearing off roofing iron, and in Auckland, high winds brought down trees and cut off power to about 500 homes in the suburbs of Takanini, Bethells Beach, Henderson and Muriwai.
A 170-year-old tree had to be felled in the Selwyn Domain in Mission Bay after it was struck by lightning.
A tree caused extensive damage when it fell through the roof of a Pakuranga home just before 4pm.
Swells of more than 8m were recorded along Auckland's western coastline.
Air New Zealand said thunder and lightning delayed services at Auckland Airport, and snow affected Dunedin services and caused widespread flight cancellations at Queenstown.
Mr O'Connor said that in Auckland, southwesterlies would remain gusty but would ease during the day, as would showers. The top temperature was expected to be 15C.
Mr Duncan said the short, cold snap could be a hint of things to come.
He said weather patterns around New Zealand were chaotic and messy.
Yesterday Aucklanders shivered in 6C in early to mid afternoon - usually the warmest time of the day.
Mr Duncan said: "This cold snap, weeks after the worst drought in 50 years ended, might help explain why we call this pattern a 'chaotic' one ... anything can happen".
This week's weather
Today: Snow, rain and wind clearing nationwide by late morning and temperatures rising.
Thursday: Possibility of heavy showers in upper North Island later in the day, temperatures expected to be double digits.
Friday: Rain clearing in the north, but due to hit the western and lower South Island.
- NZ Herald with Otago Daily Times
