Summer is coming early this week in the south and Niwa said it could be the start of a warm, dry spell leading up to the holiday season.
Central Otago is set to swelter in temperatures shy of a scorching 30C and Lincoln near Christchurch is on track to record its driest month in nearly 140 years.
The fine weather, parked over the lower North Island and entire South Island for the rest of November, threatens to leave vast tracts of parched land as soil moisture evaporates into the atmosphere.
Niwa principal scientist Chris Brandolino said the executive summary for the remainder of November and the start of December was basically hot, with less rain than we'd usually get over this period.
"The flavour or the theme for the days and weeks leading up to Christmas will be warmer than usual.
"It doesn't mean there won't be any rain in New Zealand, but it means when you look at the next 10 days its going to be a lot drier than usual at this time of the year."
Brandolino warned that although the hot, dry weather sounded great for hitting the beach, some people might not be thrilled with the news.
Brandolino said the dryness would be most intense across inland areas in the South Island like Dunedin, as well as parts of the North Island like Dargaville and the Eastern Waikato.
Except for east coast of the North Island, less than 20mm of rain is expected to fall during the rest of the month. Niwa says with an average 4mm daily moisture loss into the air much of New Zealand is expected to face a deficit of 20mm by the end of the month.
The La-Nina driven dome of fine weather is due to sit over much of the country for the next few weeks, bringing early beach days to near-record sweltering days in the south.
The Central Otago townships of Wanaka, Alexandra and Cromwell are all tipped to reach 28C in coming days.
According to the Niwa seasonal outlook temperatures are expected to sit above average across all of New Zealand for the next two months.
Rainfall totals through to the end of January are likely to be normal on both islands for this time of year, but it's likely to be drier than normal on the West Coast.
River flows and soil moisture levels are also expected to suffer in the west and east of the South Island.
MetService today said temperatures were on the rise for many places this week as a ridge of high pressure settled over the country.
Weatherwatch.co.nz said the growing high pressure looked "locked in" over both islands for the rest of the month.
It would be marked by days of calm weather, and most likely sunnier and dry conditions.
WeatherWatch.co.nz said warmer than average weather was likely across New Zealand - especially inland - beginning tomorrow, when Central Otago towns would climb towards 30C. Alexandra, Wanaka and Cromwell are all tipped to reach 28C.
The North Island would also feel the heat this week when highs around Waikato and King Country would climb into the summery mid 20s, possibly later 20s for a few pockets further inland.
However, the blue skies would be broken by afternoon deluges in Otago later this week and inland parts of both islands from the weekend and into next week.