Late autumn weather is expected to be normal as the La Nina event dissipates, Niwa principal scientist Dr James Renwick says.
The Niwa National Climate Centre's outlook for late autumn, April to June, indicates air temperatures were likely to be average or above average in the west and south of the South Island, and near average elsewhere, he said.
La Nina weakened during February and March but lower pressures than normal were expected to persist north of the country during the April to May period, with more high-pressure systems and ridges over and east of southern New Zealand. While models predicted neutral conditions from April to June, there was the possibility of an El Nino state developing in July to September.
Despite the overall pattern of near average seasonal temperatures in most places, frosts typical of late autumn will occur from time to time with the anticyclonic conditions, he said.
In inland Otago late autumn temperatures were likely to be near or above average with rainfall and river flows in the near normal range.
Coastal Otago was likely to experience near average seasonal temperatures with late autumn rainfall totals, river flows, and soil moisture levels likely to be in the normal range.
