The weather phenomenon La Nina, blamed for the heavier than usual rainfall in the past few months, is coming to an end.
The National Institute of Water and Atmospheric Research says the La Nina event, which the country has experienced for the past two summers, is fading.
The institute's principal climate scientist, James Renwick, says there should be fewer storms and weather patterns should return to normal.
"This run of storms that's come through from the north of the country, we're not saying they'll disappear completely but we should see less of them," he says.
He says the rest of autumn should be warmer than usual in the west and south of the South Island, but slightly cooler along the east coast.