About 50 regional flights in or out of Auckland Airport have been delayed or cancelled, due to a thick blanket of fog that's causing disruptions across the city.
Meanwhile, a wintry weather system is approaching the South Island from the Tasman Sea.
MetService Meteorologist Dan Corrigan says the southern Canterbury High Country and western Otago could see low snow levels by Friday.
He says they're expecting snow to be heavy around 800 metres, and that could pose a threat to livestock.
