Dunedin, which had remained slightly cooler during this week’s heatwave, made up for it early yesterday
recording 28.8degC at 2am, more than 7degC higher than the January average.
A sea breeze which had kept the city’s temperatures in the low 20s for most of the day died out just before midnight, sending the mercury soaring.
The city was the warmest place in the country at 8.30am at 25.8degC but it did not last as a southerly change moving up the South Island passed through.
It was also a hot night for some of the other major Southern towns as Oamaru (24.8degC), Queenstown (24.3degC) and Invercargill (23degC) all failed to drop below 20degC overnight.
MetService meteorologist James Millward said the unusual balmy conditions were caused by a northwesterly, which came through bringing warm air off the Southern Alps.
Dunedin was hotter at 2am than South Australian city Adelaide was at the same time.
Figures released by Niwa yesterday showed that Hanmer Forest equipment had recorded the highest temperature this week of 38.4degC on Thursday, which is also the highest temperature recorded so far this summer.
Further south, Tekapo recorded a high of 35degC on Wednesday.
Warm temperatures and high levels of humidity are forecast to be persistent until at least April.
Niwa released its outlook for February to April and is predicting above-average temperatures for all regions during the next three months.
Atmospheric circulation around the country was predicted to be characterised by slightly higher than normal pressure to the southwest and southeast of New Zealand and lower pressure than normal to the northeast of the country.
Warmer than average ocean temperatures around the whole of New Zealand would continue to contribute extra warmth, moisture, and invigorate low pressure systems as they approached the country heading into autumn, Niwa said.
