Last year there was record-breaking weather across the country and Dunedin was no exception.
According to the Niwa 2023 Annual Climate Summary report, a total of 58 locations across the country observed record or near-record annual mean temperatures. Dunedin reached a mean temperature of 12.3˚C — the city’s warmest year on record.
The report found the record temperatures observed last year, and in recent years, were consistent with climate change.
New Zealand’s long-term temperature trend has warmed at a rate of about 1.17˚C per century.
Victoria University of Wellington adjunct professor and Queenstown climate scientist Dr Jim Salinger said according to his research, and the latest findings from Niwa, the main takeaway was that the South was at the centre of these record-breaking temperatures.
"The important thing is that the record temperatures occurred in the south and east of the South Island.
"It wasn’t in Auckland in terms of warmest ever, and it goes right from Invercargill right up the coastal areas to Timaru and Christchurch.
"That was where all the records occurred generally."
New Zealand had experienced four "heatwave summers" since 2017 — periods of warmth lasting from November through to March, Dr Salinger said.
The country experienced only a single heatwave summer from the late 19th century to early 20th century.
Heatwaves used to have a one-in-300 chance of occurring, but this had now increased 10-fold to a one-in-30 chance, he said.
Because of this, about one-third of the total ice on the Southern Alps had melted in these heatwave summers — the largest ice loss over any similar period since 1949, he said.
The number of days Dunedin could expect over 25˚C had increased from eight to 12 since 1950 and the number of days below 0˚C had fallen from 15 to about five days a year, Mr Salinger said.
This meant snow days in Dunedin in the future would be just as scarce as they already were.
Queenstown only had about one snow day per year at a town level, and a similar frequency was expected for Dunedin.
Given Dunedin’s lack of frost, it was warmer than Christchurch in the winter, Mr Salinger said.
The cold air at Flagstaff and the rain west of Dunedin pushed all the cold air into inland Otago.
