Autumn has arrived and the good news is the summer temperatures are likely to continue. The bad news, so too will the rain.
In its March to May seasonal outlook, Niwa says temperatures around the country are forecast to be above average.
But the downside is that rainfall was forecast to be above normal in the North Island and in the north of the South Island.
The west and eastern areas of the South Island were expected to get normal levels.
The good news for farmers is that soil moisture levels and river flows were forecast to be above normal in the north and west of the North Island and the north and east of the South Island.
Those levels were expected to be normal in the east of the North Island and the west of the South Island.
As autumn progresses, frosts may occur from time to time in cooler locations.
The warm and humid forecast for the North Island was linked to lower than normal atmospheric pressure northwest of the country and warm ocean waters.
Weak La Niña conditions were behind much of February’s unsettled weather, but this system had reached its "decay phase", Niwa said.
As La Niña waned over the next three months, New Zealand’s regional climate was expected to be driven by the warmer-than-average ocean waters - in the Tasman Sea and Southwest Pacific - which would influence surface air temperatures and the likelihood of significant rainfall events.
Models indicated a transition towards El Niño over winter and into the September to November period.
Autumn outlook by regions
• East Otago and coastal Canterbury
Temperatures are very likely to be above average (70% chance).
Rainfall totals are about equally likely to be in the above normal range (40% chance) or near normal range (35% chance).
Soil moisture levels and river flows are most likely to be in the above normal range (55% chance).
• Inland Otago, West Coast, Alps and foothills, Southland
Temperatures are very likely to be above average (60 % chance).
Rainfall totals, soil moisture levels and river flows are all about equally likely to be near normal (40% chance) or above normal (35% chance).
• Tasman, Nelson, Marlborough, Buller
Temperatures are very likely to be above average (70% chance).
Rainfall totals, soil moisture levels and river flows are all most likely to be above normal (45 to 50% chance).
• Northland, Auckland, Waikato, Bay of Plenty
Temperatures are very likely to be above average (70% chance).
Rainfall totals are most likely to be in the above normal range (50% chance).
Soil moisture levels and river flows are most likely to be in the above normal range (50 to 55% chance).
• Central North Island, Taranaki, Whanganui, Manawatu, Wellington
Temperatures are very likely to be above average (70% chance).
Rainfall totals, soil moisture levels and river flows are all most likely to be above normal (45 to 50% chance).
• Gisborne, Hawke’s Bay, Wairarapa
Temperatures are very likely to be above average (70% chance).
Rainfall totals are most likely to above normal (45% chance).
Soil moisture levels and river flows are equally likely to be in the above normal range (40% chance) or near normal range (40% chance).
