The South Island can expect everything from rapid temperature changes to thunderstorms and snow on some roads, while the North Island is experiencing strong, gusting winds.
Meanwhile places such as Auckland are enjoying relatively fine weather, with slightly high winds in some areas.
The wildly varying weather can be put down to a "very active cold front" moving up the country, which is expected to clear New Zealand tomorrow.
"This front is really, as it comes up, is the cause of the strong northwesterly winds over many places."
Parts of Wellington, Wairarapa and Tararua are forecast to have winds gusting up to 120km/h in exposed places, and in the South Island's high country gusts are expected to hit 130km/h.
Meanwhile places such as Oamaru and Christchurch will enjoy temperature highs in the early 20s because plummeting to about 7C due to the cold front.
The front is forecast to move on to the North Island in the middle of the day tomorrow.
When that happens parts of the North Island will see heavy rain that "may approach warning criteria".
It will be followed by pleasant weather from about late Saturday through most of Sunday.
People should visit the Metservice website for up to date weather forecasts.
What to watch out for
Strong wind watch:
• Christchurch and the Canterbury plains until 7pm tonight
Strong wind warnings:
• Wellington and Wairarapa until 2am Friday
• Tararua district until 9am Friday
• Marlborough until 10pm tonight
• Canterbury high country until 9pm tonight
Heavy rain watch:
• Tararua range 1am-9am Friday
• Wellington 5am-10am Friday
• Ranges of Buller 4pm today until 5am Friday
• Headwaters of Otago lakes and river until 2pm today
Heavy rain warning:
• The range of Westland from Otira northwards until 12am Friday
• Headwaters of Canterbury lakes and rivers until 8pm tonight
• The ranges of Westland south of Otira until 9pm tonight
Heavy snow watch:
• Inland Canterbury north of Castle Hill and the Kaikōura Ranges until 6am Friday
• Clutha, North Tapanui, Central Otago and inland Dunedin until 8pm tonight
Road snowfall warning:
• Lewis Pass (SH7) until 11pm tonight
• Arthur's Pass (SH73) until 11pm tonight
• Lindis Pass (SH8) until 11pm tonight
• Porters Pass (SH73) until 11pm tonight
• Crown Range Road until 11pm tonight
• Milford Road (SH94) until 11pm tonight