After a couple of balmy days in Auckland, a temperature dip is expected to kick in shortly as a cold front moves up from the South.
A broad complex trough is expected to cover the country next week through to Thursday, with embedded low centres.
MetService meteorologist Andrew James said the change would be felt in the South Island today.
"A lot of cold and wintry weather is on the way down south," he said.
"Tonight, Queenstown and Wanaka are looking like they will get down to about 2C, which is cold for this time of year."
Taupō, Taumarunui and Tokoroa were also forecast to get down to 2C overnight on Monday, he said.
"It's going to be a cold and showery week."
Outbreaks of rain and even hail are expected over much of the country during this period, with the more persistent rain setting in about eastern parts of the South Island.
James warned that South Island motorists needed keep an eye on the forecast for roads like Arthur's Pass, Porters Pass, and Lindis Pass over coming days.
Snow was expected about eastern parts of the South Island above 400 to 500 metres, and possibly about the North Island high country above 1000 metres.
Main centre forecasts today
Partly cloudy with a shower or two. Light winds. High 22C, low 12C
Partly cloudy. Chance shower. Light winds. High 21C, 13C
Mostly cloudy with a shower or two, then rain from evening. Northwest breezes. High 21C, 10C
Partly cloudy. A shower or two from afternoon. Northwest breezes. High 21C, 12C
Rain clearing in the morning to fine spells. Showers developing overnight. Fresh northwesterlies. High 18C, 8C
Cloudy periods and chance shower. Rain and strong, cold southerlies developing toward evening. High 21C, 4C
Showers, with possible thunderstorms and hail from the afternoon, easing evening. Cold, brisk southwesterlies from late morning. High 14C, 6C