2021: New Zealand's hottest year on record

Ben McKayAAP
Of New Zealand's six main centres in 2021, Auckland was the warmest.
Camera IconOf New Zealand's six main centres in 2021, Auckland was the warmest. Credit: AP

Last year was New Zealand's hottest on record.

New Zealand's average temperature in 2021 was 13.56C, according to the National Institute of Water and Atmospheric Research's Annual Climate Summary, released on Tuesday.

Using the World Meteorological Organisation's benchmark, the year was 1.09 degrees above average, showing disturbing evidence of a warming climate.

"Seven of the past nine years have been among New Zealand's warmest on record. This trend is consistent with the overall pattern of global warming," the report states.

In addition to being the hottest year for the country as a whole, many individual places endured their hottest year since records began, including Cape Reinga, mainland New Zealand's northernmost point, Wellington airport, and Dunedin.

Auckland, at 16.5C, had its third-hottest year.

"Of the six main centres in 2021, Auckland was the warmest, Dunedin was the coolest, Wellington was the wettest, Dunedin was the driest, Tauranga was the sunniest and Hamilton was the least sunny," the report states.

Ashburton, in south Canterbury, produced the hottest single-day temperature last year when the mercury reached 39.4C on January 26.

Victoria University of Wellington climate science senior research fellow Luke Harrington said 16 places experienced their hottest-ever days in 2021, but just one station experienced its coldest day.

"That about sums up climate change in New Zealand: in the future, every cold record broken will be accompanied by another 5-10 hot records, if not more," he said.

"Things will only improve if we reduce our gross carbon dioxide and nitrous oxide emissions. Permanently, rapidly, and immediately."

The climate summary captures data beyond temperature, including wind records and quirks of weather.

"On 8 November, volcanic gases from Whakaari/White Island mixed with atmospheric moisture to create a rare phenomenon known as vog (volcanic fog)," the report states.

"Light northerly winds brought the volcanic fog onshore in Bay of Plenty, resulting in complaints about the strong smell and watery eyes."

Two tornadoes were recorded; the first was a waterspout seen from Napier's main boulevard on April 14, the same day as 5900 cloud-to-ground lightning strikes were observed as a large storm crossed North Island.

The second was a likely tornado which formed in a storm near Auckland airport on June 19.

"Approximately 240 homes were impacted, with roofs torn off, windows smashed, and power lines downed. Containers were toppled over at Ports of Auckland's South Auckland Freight Hub, killing one worker and injuring at least two others."

The highest wind gust was 222km/h at Cape Turnagain, on the North Island's southeast coast, on September 10.

The sunniest place in 2021 was New Plymouth, with 2592 hours of sunshine recorded, an average of 7.1 hours a day, edging out Napier and Nelson.

The overall temperature is calculated from a "seven-station series" with weather charted in Auckland, Masterton, Wellington, Hokitika, Nelson, Lincoln and Dunedin, with records dating back to 1908.

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