However, the southerly would not bring a major polar blast, as the cold Antarctic air was likely to miss New Zealand by a few hundred kilometres to the southeast.
By Tuesday and Wednesday, the cold snap would reach the southern and eastern North Island, with Auckland also likely to be affected. Auckland would see highs drop from near 20C in recent days to just 15C on Wednesday.
WeatherWatch said the coldest air would blow straight into Southland and Otago, with some parts failing to reach double digit temperatures.
Canterbury, Wellington and Wairarapa would also be fairly exposed.
The cold snap would bring rain to Canterbury on Tuesday, where highs would hover around 10C, but sunny weather would return on Wednesday and warm weather on Thursday.
Some heavy snow was possible in the South Island mountains but nothing heavy was expected to low levels.
By the end of next week, WeatherWatch has forecast the start of a windy westerly period that could last for a week or two, bringing warmer weather for most regions.
