Some residents in Otago and Southland woke to freezing temperatures and fresh snow with more falling this morning.
The unusual weather event comes as parts of the North Island are recording temperatures above 20 degrees.
MetService meteorologist Mmathapelo Makgabutlane said a cold front was making its way up the South Island followed by cooler air that was lowering the freezing level.
She said the summer snow was unusual, but not completely unheard of.
"For the snow, we've had a number of reports, mainly in Southland region including Fiordland. Areas that are at higher altitudes would've gotten a bit more snow, however, there were reports of snow even down to about 200m this morning."
The cooler air keeps temperatures in the lower South Island in the mid-teens today, with Gore and Invercargill expected to reach an unseasonable 13°C.
Makgabutlane said there might be snow dustings until the early hours of tomorrow, but they should clear up by sunrise.
Athol resident Dave Raynes said there was an inch of snow around his house when he got up about 6am.
The snow was on the ground for his 15-minute drive up the road to Garston for his morning coffee.
"It is white out, you can really see through the hills, snow on the ground, visibility is actually quite low as well. But it's starting to drizzle now, the snow is melting."
Judy McMillan lives in Garston, a small settlement roughly an hour's drive south of Queenstown.
"This is a lot of snow, when we woke up this morning it was snow that we think of as winter snow - snow that is going to lay not just little lakes... There's probably about 5cm of snow at the moment and it's still snowing," McMillan said.
Paul Hart who works at the Naseby Forest Recreation Area said in his 17 years in Naseby it has occasionally snowed in December.
He said by the afternoon the snow had melted and no traces were left of the wintery start to the day.
Mr Hart said the snow was welcome as last week he had to shut the Forest due to the fire risk.