Tomorrow is expected to be chilly for South Islanders as "snow showers" and strong gales are forecast.
On Wednesday, a cold change will bring some snow and cool temperatures to the South Island.
"A cold front sweeps northeast across the South Island early Wednesday morning and across the North Island later on Wednesday, followed by a strong west to southwest flow," MetService said.
Severe gales are possible for parts of central and southern New Zealand, it said.
MetService has issued a strong wind watch for Hawke's Bay, Tasman, Southland, Clutha, Dunedin and Stewart Island. West to southwest winds may approach severe gale in exposed places in these areas.
The weather forecasting agency said cold southerly showers are forecast to spread up the South Island on Wednesday bringing snow to many mountain passes. It said "snow showers" could fall as low as 200m in the south.
Road snowfall warnings have been issued for Lewis Pass (SH7), Porters Pass (SH73), Lindis Pass (SH8), Crown Range Road and Milford Road (SH94).
"Snow showers are expected to affect the road [Milford Road] above about 300 metres Wednesday morning. Expect 2 to 4cm of snow to accumulate above 600 metres with lesser amounts further down. Note, further snow possible Wednesday evening."
MetService's extended forecast:
Thursday
North Island: Showers in the west, mainly fine elsewhere South Island: Occasional rain or showers in the west and south, sometimes heavy. Mostly fine elsewhere with isolated showers.
Friday
North Island: Partly cloudy with a few showers, mostly in the west. South Island: Showers in the west and south. Mainly fine elsewhere.
Saturday
North Island: Partly cloudy with a few showers, mostly in the west. South Island: occasional rain or showers in the west and south. Mainly fine elsewhere.
Chatham Islands
Occasional showers. West to southwesterlies, strong at times.
