Icy conditions are forecast over parts of the South Island, with Canterbury getting the brunt of it.
Much of the south enjoyed a fine weekend after last week's heavy snow.
Christchurch and Canterbury recorded some of the coldest temperatures on record last week, and frigid conditions are again likely.
"We're barely into winter and once again the bitter cold is set to return," said WeatherWatch weather analyst Richard Green. "It's the type of cold that is raw and can really get into your bones if you're not prepared, as the wind this week is likely to pick up.
"Normally the coldest weather comes after the shortest day but this year Mother Nature has obviously thought she'd take a different approach. It might be a mix of showers of rain, hail, sleet and snow in some cases but whatever falls it'll be the temperature that bites."
