New Zealand charts hottest year in 2022

New Zealand has again charted its hottest year on record, with 2022 taking the place of 2021 in the climate change-driven record books.

New Zealand's nationwide average temperature was 13.76 degrees in 2022, according to climate agency NIWA, which was 0.2 degrees higher than last year.

Not since 2012 has New Zealand had a below baseline average year, which NIWA's Annual Climate Summary report, released on Wednesday, says is "a trend that is consistent with climate change".

"There were a myriad of climate drivers that contributed to the unusual warmth and wetness in 2022," the report states.

"The primary driver was La Nina, marked by cooler than average ocean temperatures in the central and eastern equatorial Pacific."

La Nina affects New Zealand in different ways to Australia, causing it to endure "more sub-tropical, northeasterly winds than normal, driving up air and sea temperatures".

Last year was the third straight La Nina year, which has not occurred in New Zealand since 1998-2000.

La Nina conditions expected to ease in 2023, and possibly swing to El Nino later this year.

The NIWA report authors say above-average coastal sea surface temperatures - which reached marine heatwave levels - also impacted weather conditions for Kiwis.

Last year was also New Zealand's eighth-wettest according to records dating back to 1960, including its warmest and wettest-ever winter.

Those conditions combined to produce a horror snow season for North Island ski fields, with Ruapehu-based operators forced into administration, while South Island ski fields enjoyed a bumper season.

The report also revealed regional highs and lows, with Taranaki named the sunniest place in New Zealand with New Plymouth enjoying an average of 7.3 hours of sunshine a day.

The consistently warmest place in New Zealand was the coastal Northland town of Leigh, at 18 degrees.

Dozens of places - including Auckland, Hamilton, Tauranga, Wellington, and tourist locations including Milford Sound, Franz Josef - charted their warmest years since records began.

Despite the overall warmth, nowhere in New Zealand hit a single-day spike of 35 degrees, for the first time in 15 years.

The hottest single-day temperature of the year was 34.7 degrees, charted at Lake Karapiro in the Waikato, on January 3, the lowest figure since 2007.

The coldest measurement at a weather station was -11.6 at Mount Cook Airport on July 17.

NIWA's headline national figure is taken from its "seven-station" series, which records temperatures from stations based on different pockets of the country; Auckland, Masteron, Wellington, Hokitika, Nelson, Lincoln and Dunedin.