Long-standing winter temperature records have been broken throughout Otago.
It has been the warmest winter on record for the country and for most parts of Otago, Niwa confirmed yesterday.
Niwa principal scientist Dr Brett Mullan said winter's mean temperatures were well above average throughout Southland and Otago, except for South Otago.
The nationwide average winter temperature was 9.5degC - 1.2degC above the winter average.
Dunedin's Musselburgh 66-year mean winter temperature record was broken with 8.4degC, which was 1.3degC warmer than normal.
Also broken were Oamaru's 105-year record with 8.4degC, 1.3degC warmer than normal, and Alexandra's 30-year record with 5.7degC recorded, 1.5degC warmer.
Mean maximum air temperature records were also broken with 11.9degC at Musselburgh, 10.3degC in Wanaka and 10.1degC in Tara Hills.
The records were broken because higher-than-normal pressures to the north, west and south of New Zealand caused more northerly and northeasterly air flow than usual, Dr Mullen said.
That caused the largely settled conditions across the country for much of July and August, resulting in high mean temperatures for the time of year in many locations.
However, an early winter east-southeasterly flow over the South Island contributed to well-above-normal rainfall east of the Southern Alps, he said.
Records were broken as Alexandra recorded 141mm, 175% of normal, and nearby Lauder 141mm, 179% of normal.
Cromwell recorded its second-highest winter rainfall of 164mm and Ranfurly its third-highest at 142mm.
While Dunedin recorded above-normal rainfall for winter of 234mm, it was the driest of New Zealand's six main centres, behind Christchurch's 285mm and Wellington's 470mm.
Christchurch beat Dunedin to the coldest winter city with 7.7degC, compared with Dunedin's 8.4degC.
Contributing to the warm winter in Otago were record-breaking August mean temperatures of 7.7degC in Wanaka, 6.3degC in Ranfurly, 9.5degC in Dunedin and 9.1degC at Nugget Point.
Mean maximum air temperatures and mean minimums were also high throughout the district, with most places recording their second, third or fourth-highest since records began.
Dunedin was also the driest of the six main centres in August with 30mm, only 55% of normal.
