A freezing front moving up the country will bring heavy snow and gales with it this weekend.
Metservice has issued its first heavy snow warning of the winter, forecasting 10 to 20cm to fall above 200m in Southland and Fiordland from Saturday night.
In some places the snow would fall to nearly sea level, forecaster Claire Flynn said.
The agency issued road snowfall warnings for all of the mountain passes, as well as the Desert Road, where up to 5cm of snow could accumulate around the summit.
The poor weather was due to a cold front that was starting to move up the country, Ms Flynn said.
It would also bring strong winds to most of the North Island, with wind warnings in place in southern Hawke's Bay and Tararua.
People living in those regions could expect gusts of up to 120km/h, Ms Flynn said.
There would be little reprieve after the front had blown through, with another one following in its wake on Monday, she said.
The Transport Agency warned drivers to take extra care on central North Island roads.
"Roads throughout the Central Plateau are likely to be affected by snow and ice today and right through the weekend," regional performance manager Karen Boyt said.
"We don't want anyone's weekend to end in tragedy, and we're urging people to keep an eye on the conditions and to consider delaying travel if the weather deteriorates."