KEY POINTS:
Snow continues to fall in Dunedin and central Otago but all roads are open in the South Island.
Transit's coastal Otago area engineer Peter Robinson said there is some flooding on State Highway One south of Gore and on State Highway 90.
He said other parts like Te Anau were closed to towing vehicles.
"Everywhere, it's either chains essential or extreme care. Drivers need to check the conditions before they leave. The conditions could change at any time," he said.
Mr Robinson said snow drifts were effecting Middlemarch and the road could close at any time.
Otago area engineer John Jarvis said chains are required for the Haast Pass and driving at night is not recommended.
"In the alpine areas there is ice so extreme care is needed. The conditions are changing rapidly," Mr Jarvis said.
Metservice forecaster Ian Miller said conditions are improving in the South Island.
"Drivers should be prepared and check the highway conditions but this should be the last gasp of cold wintry weather for the time," Mr Miller said.
He said the cold weather was set to move up the east coast of the North Island with snow expected on parts of the Desert Rd.
Conditions should improve in the South Island but snow showers and sleet are expected in Christchurch today.
