MetService says a cold south-westerly is making its way up the country from Southland.
Snow showers are affecting parts of South Fiordland, Southland, and southern parts of Otago, including Clutha and Dunedin, and are expected to ease before dawn tomorrow.
Meteorologist Rob Kerr said the south-westerly flow was bringing some cold Arctic air.
He said there will be a few fronts sweeping over the country in the next 24 to 36 hours and although the broad trend is one of easing there will be a few intense periods.
Mr Kerr said most of the shower activity tomorrow would occur in the Wellington region and the East Coast of the North Island.