Flights in and out of Queenstown Airport have resumed after heavy snow, but travellers are warned to expect delays throughout the day.
Snow on the runway has caused flights to be put on hold today, with many roads closed for the same reason.
Warnings on the airport website said roads around the airport were icy and extra care was needed.
Passengers were told to contact airlines directly check flights.
"Our teams are clearing the snow and applying de-icing treatments, please take extra care," a message on the website stated.
The heavy dumping of snow also brought warnings for all the main passes, and the Dunedin to Waitati Highway.
Heavy snow warnings were also in place for parts of Otago and Southland, and there are watches from Hawke's Bay to Canterbury.
Tom Adams from MetService said it was "absolutely freezing" with visibility and icy roads causing hazards.
Drivers were warned to take extra care and farmers to check on livestock.
"There are a few roads closed so we would urge people to check the NZTA website before heading out," Adams said.
"Some of the roads have snow that has melted overnight and frozen so they are pretty icy."
MetService forecaster Lisa Murray said cold air was coming off the polar ice cap, turning rain to snow, especially at high levels in the south.
She said snow flurries or sleet could fall at low levels or sea level, but it wouldn't stay on the ground.
MetService expected a strong, cold southwesterly flow over southern New Zealand, with snow falling to low levels last night and this morning.
Heavy snow was expected above 400 metres in southern Otago and the Southland hills, and around 10 to 15cm was expected by 9am.
This is in addition to any snow that has already fallen.
Severe southwest gale warnings were issued for Clutha and Dunedin through to this evening.