Weather ahead across the country: 

Monday:

A front moves across central and northern New Zealand, bringing showers.  Thunderstorms and hail are possible for the upper South Island, and central and eastern parts of the North Island.  
Showery southwesterlies for Auckland.
A cool southerly spreads up eastern parts of the South Island and onto the lower North Island.
Place to be, West Coast of the South Island, with plenty of sunshine and temperatures in  the low twenties.

Tuesday (New Years Eve):

A wet and windy day ahead for eastern regions from Canterbury to Gisborne, as a front brings strong southerlies and rain.
A Heavy Rain Watch is in force for northern Hawke's Bay and southern Gisborne.
Temperatures in most places are average, or for eastern regions a few degrees below average.
Showers and southwesterlies ease over the upper North Island later in the day, looking good for Auckland to see the new year in.
Place to be, Queenstown, with a sunny day, and a daytime maximum of 20 degrees.

Wednesday (New Years Day):

An unsettled showery southwest flow affects central and northern New Zealand, with average temperatures in most regions.
A ridge builds over the lower South Island, 
Place to be, Queenstown once again, with partly cloudy conditions and a day time maximum of 21 degrees.