A bitter cold snap bringing snow, rain and gales is set to plunge the country into the middle of winter.
An Antarctic blast is just 48 hours away and snow is expected to fall on southern towns and cities on Thursday.
The MetService is expecting snow to low levels over the southern regions.
Niwa says Friday's temperatures will be like those normally experienced in the middle of winter.
"It is the lowest freezing levels that we've seen so far this year," MetService forecaster April Clark said.
Snow is forecast to fall in Southland, Canterbury, parts of central Otago and Dunedin's hill suburbs.
Clark says it is too early to tell how much snow would fall, but everywhere would notice the sudden cold snap as temperatures start to spiral downwards on Thursday.
Before the snow, though, rain and wind would hit parts of New Zealand. Regions on the western coasts of both islands are expected to bear the brunt of the wet weather.
A number of watches and warnings are expected to be issued ahead of the coming deluge.
This would be followed by a couple of days of bitterly cold weather as snow and sleet covered the lower South Island.
Snow is expected to start falling in Queenstown and Alexandra on Friday. Temperatures were set to plummet to single digit highs of just 7C this weekend.
Clark said everywhere would notice the sudden wintry change as the air laced with an icy chill enveloped the country.
