The National Climate Centre says this summer is set to be mild but slightly warmer than normal.
NIWA's seasonal climate outlook for December to February predicts above average temperatures for much of New Zealand, due to anti-cylones off the east coast.
Dr James Renwick says rainfall should be normal with the exception of the eastern part of the South Island, which may experience drought-like conditions later in the season.
However, he says the west coast of the South Island may receive more rain than normal.
