Snow, rain and plummeting temperatures are expected in parts of the country as a cold front hits next week.

Southland, Otago and Fiordland will bear the brunt of the cold snap when a low moves in from the Southern Ocean, bringing winter conditions by Tuesday, said WeatherWatch.co.nz head analyst Philip Duncan.

"It will be a significant one (front) and looks like it will be quite brutal for some areas.

"There's quite a nasty storm in Southern Ocean. The main front will move into the west coast of the North island too, including Auckland,'' he said.

Snow showers were likely in Queenstown along with heavy rain in the lower South Island and west coasts of both islands.

Aucklanders could expect cold showery conditions as the front moved up the country, with temperatures dropping from an average of about 17 to 13 degrees during the day in the middle of the week.

Temperatures will plummet in the lower south, reaching single digits in parts of Southland and Otago. A high of only 4 degrees was forecast for Tuesday and possible thunderstorms, said Mr Duncan.

The large size of the front meant it was expected hang around for several days.

A high was then forecast for the North Island from the end of the week, bringing a return to to autumn conditions.

- APNZ