A southwesterly cold blast is forecast for early next week by MetService.
Meteorologist John Law said a fleeting ridge of high pressure will bring a dry start to the weekend.
But a low from the North Tasman Sea and an active front from the Southern Ocean will bring wet weather for much of New Zealand from Sunday.
Mr Law said by Monday, a very cold southwesterly is expected to spread across New Zealand, bringing snow to near sea level in the far south.
He said overnight temperatures will be almost freezing and daytime temperatures will struggle to get into double figures for much of the country next week.