With five days left of this summer, it's set to become New Zealand's hottest summer in history.
That's according to NIWA who say unless the remaining days of the season are "unprecedentdly cold" this summer will eclipse a record held for more than 80 years.
Until now, the hottest summer on record is 1934/35 where the temperature was 1.8°C above the 1981-2010 average. This summer is currently running at 2.3°C, 0.5°C above the previous record.
"This has been a striking feature on both a regional and global climate scale," NIWA meteorologist Ben Noll says.
"It began at the end of November last year and has now persisted for three months. There have been three distinct peaks when sea surface temperatures were between 2 to 4°C above average: mid-December, late January and mid-late February."
Mr Noll says there were even some sea surface temperatures six or seven degrees above average.
"This represented some of the largest ocean temperature anomalies anywhere in the world over the last several months."
NIWA principal climate scientist Dr Brett Mullan says the persistence of anticyclones and north-easterly winds have also been a feature of this summer.
Summer standouts so far
• 108 places across New Zealand recorded their hottest summer on record, 21 their 2nd hottest and eight their 3rd hottest.
• In Alexandra on January 30 the temperature reached 38.7 °C. On the same day Clyde got to 37.6, Middlemarch 37.4 and Cheviot 37.3 – together these comprise the hottest temperatures of summer.
• Wellington has had 17 days above 25°C this summer – the average is two.
• Auckland usually has 29 summer days above 25°C, this year there have been 47 – the highest since records began at Auckland Airport in 1966.
• Invercargill recorded three consecutive days over 30°C in January. It’s never done that for two days in a row, let alone three.
• Cromwell has topped 25°C for 56 days – normal is 35 days.
• Dew point temperature – the meteorological measurement combining humidity and temperature – failed to drop below 19°C in Auckland from February 10-15, making it a rare 115-hour period of very high humidity.
• In Wellington a dew point temperature of 22°C at 6pm on February 11, the highest dew point on record for the city.
• Mahia, Appleby and Waipara West have had their wettest summers on record.