Weather: Cold snap blasts New Zealand this weekend

New Zealand is in for a wet and cold weekend as a cold snap blasts the country, bringing sub-zero temperatures in its wake.

The cold southerly change is sweeping up the country on Saturday, reaching Christchurch around midday and Wellington on Saturday evening. It will see Wanaka dropping to -3C overnight, with both Timaru and Queenstown down to -4C.

"Another chilly one for the South Island on Saturday, as snow looks likely to lower down to 400 metres for parts of Southland, Otago, Southern Lakes and Canterbury High Country," MetService says on Facebook.

"Overnight into Sunday will see very cold minimums for the South Island, and severe frosts are possible for parts of Otago and Canterbury High Country - Alexandra dropping to -6C!"

Rain moves in over the North Island on Saturday night, with snow as low as 900-metres in the lower parts. Sunday will be wet with cold, showery southwesterlies.

Road snow warnings have been issued for roads in the South Island, including Lewis Pass (SH7), Arthur's Pass (SH73), Porters Pass (SH73), Haast Pass (SH6), Lindis Pass (SH8), Crown Range Road, and Milford Road (SH94).

Photos and video from the South Island show the bad weather arriving.

"As the cold front moved up the South Island this morning, it pushed through Mount Cook around 10am and the temperature dropped to zero at 10:30am. The rain then turned to snow - as can be seen on this webcam loop," MetService posted.