A warm year but not the hottest
The Gisborne region's heat helped make 2020 New Zealand's seventh-warmest year on record, according to the National Institute of Water and Atmospheric Research (Niwa).
The nationwide average temperature for 2020, calculated using stations in Niwa's seven-station temperature series which began in 1909, was 13.24°C (0.63°C above the 1981–2010 annual average).
The National Climate Database shows Gisborne had its third-equal warmest year for the same period.
The hottest spell of the year took hold over New Zealand from late January to early February, with several locations observing their highest daily maximum and daily minimum temperatures on record.
The highest temperature of 2020 was recorded by Niwa on January 31 at Gisborne, by its instruments near the Waipaoa Water Augmentation Plant in Bushmere Rd.
The maximum there was 38.2°C — New Zealand's fifth-highest January temperature on record, and the country's 19th-equal hottest temperature on record for all months.
However, the Bushmere Road site regularly records higher temperatures than the MetService site at the airport, by half a degree in winter and more than a degree in the summer months.
While it may have been the country's seventh warmest year according to the Niwa records, MetService records for Gisborne dating back to 1909 indicate 2020 was the third-equal warmest local year.
Last year recorded a mean daily average of 15.2 degrees — the same as the previous two years.
The warmest Gisborne year was 1998 with a mean daily temperature of 15.7 degrees, and the second warmest local year was 2016, with 15.3 degrees.
Niwa's annual summary says the 23 degrees recorded at its site on August 31 was the highest August temperature here since records first began in 1905.
Niwa says New Zealand's hottest year on record remains 2016, when the nationwide average temperature was 13.45°C (0.84°C above the 1981–2010 annual average).
Based on the seven-station series, 2020 featured six months with above average temperatures (greater than +0.50°C of average), six months with near average temperatures (within -0.50°C to +0.50°C of average), and no months with below average temperatures (less than -0.50°C of average).
It has now been 47 months since New Zealand has had a month with below average temperatures (the last such month was January 2017).
Furthermore, six of the past eight years have been among New Zealand's hottest on record. Niwa says this trend is consistent with the overall pattern of global warming.
In Gisborne, six of the past eight years have also been among the warmest on local record. - RH