Snowfall is easing in South Island, but the cold snap is moving north.

MetService says no further snow showers are expected in Lewis, Arthur's or Porters Passes in the South Island.

Strong, cold southwesterlies took temperatures down to 2 degrees in Dunedin and Invercargill overnight.

Wanaka touched zero degrees, and parts of State Highway 87 and SH1 are blocked by snow.

Flights in and out of Queenstown Airport are on hold, causing delays for travellers.

Snow on the runway has caused problems, and roads around the airport are closed for the same reason.

On the Desert Road in the North Island, 2 to 4 centimetres of snow may build up above 800 metres until 1pm then showers should ease.

More snow showers are possible between 4pm and 7pm this evening, with up to 1 centimetre settling on the road.

After the snow comes the freezing temperatures. Icy temps tonight, but even colder on Sun night. Experimental map-please give feedback! ^TA pic.twitter.com/x9o0icPD0G

— MetService (@MetService) May 19, 2017