Temperatures are likely to be average or above average for the next three months, except for the east of the North Island, where it's most likely to be warmer than average.
Climate researchers at NIWA on Friday released their seasonal climate outlook for August to October - the transition into spring.
While the east of the North Island is most likely to be warmer, it's also likely to get normal or above normal rainfall.
Rainfall should be normal or below normal in the west of the North Island and in the north of the South Island, and near-normal everywhere else.
NIWA said the outlook is based on probabilities and is an indication of weather patterns over a longer period.
"A colder than average end of winter and beginning of spring is the least likely outcome, so that's the lowest ranking. More likely than anything, temperatures will be above average of near average," forecaster Chris Brandolino said.
The chance of a potentially disruptive El Nino weather pattern occurring in the next three seasons is high, but the chance of it developing this spring is lessening.
EL Nino is created by the interaction of atmospheric and ocean conditions.
Mr Brandolino said that combination was not evident and and other El Nino indicators had also weakened in the last month.