Not only was the 2017/2018 summer New Zealand's hottest on record, a meteorologist says a particularly tropical week in Auckland was comparable to living in Fiji.

Niwa's Ben Noll said Auckland endured climate conditions similar to Fiji or New Caledonia for a near five-day period from February 5.

That was when the dew point, a measure of both humidity and temperature, for Auckland failed to drop below 19 degrees for 115 hours.

"It was as if you were transported 5 degrees or 10 degrees north in latitude for a period of time."

Overall, it's been the country's hottest summer on record. And there are still five days to go.

Data released on Friday from climate agency Niwa shows temperatures are running 2.3 degrees Celsius above average.

You have to go back more than 80 years to 1934/1935 to find our next hottest summer - which was still half a degree colder than what Kiwis are experiencing now.

And there's still five days left in summer for this year's record-breaking average to push higher.

Well-above average sea temperatures around New Zealand have been credited - or blamed - for boosting summer highs.
Noll said since November last year there have been "three distinct peaks when sea surface temperatures were between 2 to 4 degrees above average".

"Mid-December, late January and mid-late February."

In some areas sea temperatures spiked at  6 to 7C above average.

"This represented some of the largest ocean temperature anomalies anywhere in the world over the last several months."

With this season's balmy to uncomfortably hot temperatures have come extreme weather events.

Warmer seas have allowed marauding subtropical cyclones like Gita to barrel south onto New Zealand, endangering lives and damaging land and property.

Auckland even turned tropical for a five day period starting February 5, Noll says. Auckland had more in common with Fiji or New Caledonia. 

OUR HOTTEST SUMMER

• 108 places across New Zealand recorded their hottest summer on record, 21 their 2nd hottest and 8 their 3rd hottest.
• In Alexandra on January 30 the temperature reached 38.7 degrees. 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 degrees this summer – their average is two.
• Auckland usually has 29 summer days above 25 degrees, this year there have been 47 – the highest since records began at Auckland Airport in 1966.
• Christchurch had temperature highs of 33, 32 and 35 degrees in the months of December, January and February 2018 with an average temperature of 23 degrees. About 261mm of rainfall was recorded from December to date.  
• Invercargill recorded three consecutive days over 30 degrees in January. It's never done that for two days in a row, let alone three.
• Cromwell has topped 25 degrees for 56 days – normal is 35 days.
• Auckland's dew point temperatures (humidity) failed to drop below 19 degrees for five days in February making for a rare 115-hour period of very high humidity.
• Wellington copped a dew point temperature of 22 degrees 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.

(Source: Stuff)