The chilly blast has come at a bad time for Southern dairy farmers, Federated Farmers say.
Southland and Otago residents woke this morning to a white dusting across the city and temperatures hovering around 2 degrees Celcius.
Metservice forecast wintery showers for the morning with wind gusts of up to 100km later in the day. There are reports of snow settling in Gore, Lumsden, Mossburn and Dipton.
Provincial president Russell MacPherson said there were a lot of people in Otago and Southland in the thick of calving and temperatures dropping below zero degrees would be challenging.
"Whilst the snow is blanketing pastures it's the wind chill that is really going to test us. The bitter chill cuts through you and new born calves won't be able to cope for long in these conditions.
Farmers would be busy feeding out to stock and pushing them to shelter to get them through, he said.
The main focus would be rushing new born calves to to the calving shed to keep them warm.
The wild weather has also wrecked havoc on powerlines in the south over night.
PowerNet networks general manager Keith Burns said about 200 people in Southland were affected by power outages.
The Southern region from Te Anau, through Mossburn to Dipton was one of the worst affected, with Balclutha area also being hit hard by weather caused faults, he said.
Outages were caused by fallen trees, debris being blown into lines, as well as fuses blowing because of increased heater use, he said.
Almost all of the faults had been resolved about 10am, he said.
Heavy snow on the roads caused trouble for one truck driver in Clinton this morning when a truck and trailer had rolled over in icy conditions.
No other details were available at this stage.
The New Zealand Transport Agency is urging caution on several South Island highways due to snow and ice.
Chains are essential on SH94 from Te Anau to Mossburn, SH85 from Kyeburn to Omakau, SH8 Tarras to Omarama, SH8 Clarksville to Raes Junction, SH7 Hanmer Turnoff to Springs Junction and SH73 Arthus Pass to Otira.
Caution is also urged on SH1 Dunedin to Waitati, SH6 Kingston to Dipton, SH1 Mosgiel to Andersons Bay and SH85 Kyeburn to Palmerston.
Snow started falling in Queenstown shortly after 9am this morning, with snow on the crown range between Queenstown and Wanaka and motorists are advised to carry chains.
Chains are essential on the Lindis Pass and SH8 between Alexandra and Raes Junction and SH85 between Alexandra and Ranfurly.
The heavy snow has also closed schools and disrupted traffic around the southern South Island.
Most schools in Dunedin had been closed or were to have 10am starts.
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