MetService is warning a wintery blast is on the way with much of the country to experience cold temperatures, strong winds and showers overnight.
Upto 18 centimetres of snow is expected to fall on upper parts of the Milford Road by early tomorrow morning and snow is also forecast for the Lindis and Arthurs Pass and the Tararua Ranges in the lower North Island.
Strong northwest winds are expected to hit parts of Canterbury and Wellington this evening.
Duty forecaster Carl Loots said a series of southerly fronts was bringing the first significant cold spell for the year.
"We're going to see a series of cold fronts moving over the country from the south over the next 24 to 48 hours, bringing with it is going to be much colder conditions, snow down to about 300 metres in the lower South Island."
Mr Loots said he expected the weather would improve by Wednesday.