Snow at Jollies Hill, State Highway 6, in Southland on Monday. Photo: Supplied / NZTA
Snowfall warnings are in place for South Island alpine passes and inland roads.
The Transport Agency is warning motorists to prepare for disruption with snow already falling in some places, and frost and ice likely in coming days.
Warnings are already in effect on State Highway 85 from Ranfurly to Becks in Central Otago, and on State Highway 94 in Southland from Mossburn to Te Anau and Te Anau to Milford Sound.
About 10cm of snow was forecast to fall on Porters Pass above 600m tomorrow morning and parts of State Highway 73 could be closed as a result.
Snow was also expected to fall on inland Canterbury above 300m Tuesday morning.
The agency's system manager Mark Pinner said very frosty conditions were expected in the following days, which meant icy roads were likely.
Snow at Gorge Hill on State Highway 94 between Te Anau and Mossburn. Photo: Supplied / NZTA
"Our crews will be out and ready to clear snow and lay grit or a de-icing agent on icy roads," Pinner said.
"If conditions are considered bad enough, temporary speed reductions or road closures are also possible.
"We want to remind motorists to drive with care and to the conditions - including being visible, reducing speed, adjusting the travelling distance behind other motorists and avoiding sudden braking or turning movements."
MetService was also warning of snow on the Crown Range between Wānaka and Queenstown.
Further warnings come into effect this afternoon for the Lindis Pass and overnight and into the morning for Dunedin's Northern Motorway, Arthur's Pass, Porters Pass and Lewis Pass.
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