It’s been a number of weeks since New Zealand had widespread frosts but thanks to a stronger than expected Polar surge over the past 24 hours temperatures are tonight expected to plummet below zero for a number of regions.

Head weather analyst Philip Duncan says places from Auckland southwards will see frosts overnight.  “Waikato, Bay of Plenty, Central Plateau, King Country, inland Taranaki, Manawatu, Kapiti, inland parts of the South Island and regions south of Banks Peninsula are all likely to see frosts developing tonight and again tomorrow night”.

“Very light frosts are even possible in western parts of Auckland and that risk will increase overnight Sunday/Monday morning”.

Along the east coast of New Zealand from Christchurch to Gisborne southerly winds and showers will keep most places slightly above zero but sleet is still possible to near sea level especially from North Canterbury to Wellington and coastal Wairarapa.

Mr Duncan says the frosts may come as a bit of a surprise after a relatively mild few weeks thanks to a number of lows in the sub-tropics and northern Tasman Sea.  “These lows have brought plenty of damp, humid, air to the country with overnight lows dropping no where near frost levels in a number of normally frosty areas”.

“Inland, western and north-facing regions will be most exposed to frosts tonight with much of the country vulnerable tomorrow night.  By Monday another low in the Tasman will spread warmer nor’westers over the country which should warm things up again”.