Snow and sleet showers are hitting parts of the South today as a cold wave of icy winter weather sweeps north.
The MetService says snow is also falling near Mt Cook, and severe weather warnings are in place for some areas.
The forecast worsens as the week goes on and snow showers could reach Dunedin and Christchurch tomorrow. Heavier falls are expected in the hill country around those cities.
MetService says a bitterly cold southerly flow is expected to affect the lower South Island from today through to Wednesday.
Snow showers are expected to near sea level about southern Fiordland, Southland and Clutha, where 20 to 40cm is expected to accumulate above 100 metres.
The New Zealand Transport Agency advises motorists to carry chains if they intend to travel any of the alpine passes.
The snow is expected to reach the North Island in the middle of the week, with falls in eastern parts down to 200 metres.
"It is shaping up to be a cold week," MetService Meteorologist John Law said.
"The combination of these cold temperatures with the showery airstream moving across New Zealand does mean we are likely to have snow falling to lower levels in many places."
The winterless north will even be brought back into season as the chilly air reaches Northland and Auckland on Wednesday, bringing cold days and colder nights as temperatures drop to three or four degrees overnight.
Parts of Waikato and the Central Plateau are forecast to drop below freezing.
And while the weather will be wintry down south, it's unlikely to reach the record lows of last month.
"Look out for more cold nights coming up across inland Canterbury and Otago," Mr Law said.
"But without a deep layer of snow to keep the lower levels of the air incredibly cold, temperatures are forecast to drop to -9 or -10 for the likes of Twizel, rather than the -20 that was recorded last month."
The cold conditions earlier prompted a warning for southern motorists owing to black ice in many areas.
