2017 was NZ's fifth-warmest year since records began.
Last year was the fifth warmest year on record in New Zealand and one in which swings between extremes toppled longstanding records nationwide.
Niwa's annual climate summary for 2017, released on Monday, shows the year's weather was hard to pin down: it was largely defined by warm temperatures and high rainfall, but ended with record-breaking dry-spells and meteorological drought.
For most of the country, 2017 was warmer and wetter than usual, the report says. All six major cities had clocked up their usual annual rainfall before the end of September and had been on track for record wet years.2017 was a wet year for much of the country.
Many areas broke or nearly broke various high temperature records. No locations broke low annual temperature records.
The year's weather was caused in large part by prevailing high pressure patterns in the east, with northerly winds. The year ended with a marine heatwave and a high pressure system, leading to warm, settled conditions.
Of the major cities, Auckland was the warmest, Dunedin the coldest and driest, Tauranga the wettest and sunniest, and Wellington the most dim.
The average air temperature nationwide was 13.15C, about 0.5C above the long term average. That made it the fifth warmest year since 1909, beaten by 2016, 2013, 1999 and 1998.
While much of the South Island and lower North Island had near normal temperatures, temperatures were above average further north.
The exceptions to the overall trend were in the deep south - Southland and Central Otago were notably drier than usual.