Revellers planning to celebrate the new decade will be happy to know most of the main centres look set to ring in 2020 with fine, mild weather, according to the WeatherWatch 10-day forecast.
Though some rain is possible, and a bit of wind in the south, the rest of the country will be mild and sunny.
• New Year's Eve weather: Outlook good for summer-starved Kiwis
• Christmas Day weather forecast: Sunny for some, thunderstorms for others
• Boxing Day weather: The unsettled summer continues
• Weather: Rain and wind around in most regions for next few days
Auckland is forecast to enjoy a high of 24C on New Year's Eve, and 23 on New Year's Day. Both days will be mostly sunny and there will be a mild overnight low of 15C.
Christchurch takes the top temperature on New Year's Day, jumping from 21C and mostly sunny, but with a small chance of rain on New Year's Eve, to a whopping 34C on Wednesday because of a south-west change.
Whangārei will hit 26C on New Year's Eve and 27C on New Year's Day, though it will be partly cloudy with a slim chance of rain.
Hamilton is set to top 26C on both days with no chance of rain, though the overnight low will drop to a fresh 12C.
In popular holiday spot Tauranga, temperatures will range between 24C and 26C for New Year's Eve and New Year's Day, and it will be mostly sunny with no rain for beachgoers at Mount Maunganui.
The overnight low for revellers is 15C.
Wellington and Dunedin only make the high teens and low 20s on Tuesday and Wednesday, with a 40 per cent chance of rain in Dunedin on New Year's Day.
Windy conditions may develop through the South Island interior in some places as the air is squeezed through the mountains and valleys ahead of a weak cold front coming in after midnight in the deep south, WeatherWatch says.
Latest data shows clouds will thicken later in the day there but drizzle or showers may not arrive until after midnight.
Fiordland may have rain developing before midnight.
• The latest update will be provided on Monday at WeatherWatch.co.nz, or try RuralWeather.co.nz for more free weather data.