On the eve of the first official day of winter, temperatures hit 22degC in Dunedin.
The MetService recorded temperatures of 22.5degC at Dunedin Airport, 22.3degC in the city centre, 22.2degC in Balclutha and 22degC in Millers Flat about 1pm yesterday.
Meteorologist Lewis Ferris said it was the hottest day of May for Dunedin and the hottest temperature in the country yesterday, but sadly, it was not a temperature record.
"There were a few other places across eastern areas of both the North Island and the South Island that reached over 20degC.
"It was caused by quite a warm slab of air from the tropics that was being dragged over the country.
"Northerly winds and that influx of warm air is basically what has driven it.
"It was especially noticeable in Wellington [early yesterday morning] when we had our highest temperature around midnight as that warm air came on."
He said the Dunedin temperatures were "well above" the average May maximum temperature, which was about 14degC.
"You would need to get up in the order of the mid-20s to get near the May record territory.
"Given how close it was to June, when winter starts, it was very unusual."
Mr Ferris said another weather system was on its way towards New Zealand and would bring some cloud and rain over the next few days.
