Dunedin and Cromwell rewrote the record books last month as air temperatures soared across Otago.
Statistics released by the National Institute of Weather and Atmospheric Research stated New Zealand's February air mean temperature of 19.5degC to be the second-warmest on record.
Dunedin recorded highs at both Niwa weather stations for mean air temperature in February, 17.8degC at Dunedin airport and 17.7degC at Musselburgh. Those temperatures were 3degC and 2.7degC above normal, respectively.
Cromwell also hit a mean air temperature high for the month of February, recording 20.7degC, 3.4degC above normal.
The hub of Central Otago recorded its highest mean maximum air temperature of 28.2degC, 4degC above normal.
Seven Otago stations at Wanaka, Ranfurly, Lauder, Tara Hills, Cromwell, Dunedin and Nugget Point recorded highs for mean minimum air temperature.
Niwa National Climate Centre principal scientist Chris Brandolino said the temperatures could be attributed to a northwest air flow for the south that made it hotter and drier than normal.
The warm weather was likely to continue in the south.
"For the next three months as a whole ... the most likely outcome is for temperatures to be warmer than usual,'' Mr Brandolino said.
He said El Nino was a factor late last year but not so much in February.
"El Nino typically causes more westerly winds in the summer,'' Mr Brandolino said.
"I would say it's atypical of a normal El Nino pattern.''
University of Otago Emeritus Prof Blair Fitzharris said February's warmth was "a bit of a surprise'' given it was an El Nino year.
"It is a bit odd for an El Nino. Normally with an El Nino we would be windier and wetter.''
Prof Fitzharris attributed the warm weather to a warmer than normal Indian Ocean, which was affecting Australia.
"They [Australia] get an influx of warm air from the Indian Ocean. It migrates from the west over to us.''
He also felt global warming had played a part in New Zealand's warmer temperatures overall.
"The last 12 months or so have been the warmest on record,'' Prof Fitzharris said.
"There have been a whole series of years in the last 15 years that have clearly been warmer than anything we've had before. If this sort of pattern continues ... we're going to get some years which are going to break records.''
