Niwa predicts 'weather rollercoaster' for Wellington this autumn

Wellington City. Photo / Mark Mitchell

Wellington can expect a "weather roller-coaster" over the month of autumn, with periods of warmth, rain and a few cold snaps.

The National Institute of Water and Atmospheric Research (NIWA) released its Seasonal climate outlook on Monday, the first day of autumn.

For the Wellington region, it predicted temperatures to be near average (40 per cent chance) or above average (40 per cent chance).

Niwa meteorologist Ben Noll said autumn conditions in the capital would be variable.

"It's a bit of an up-and-down pattern for Wellington, a bit of a weather rollercoaster through the month of March and then into April," he said.

"As we go through the next few weeks there will be some cold snaps affecting Wellington but as we go towards the month of April things will even back out and we'll have some warmer weather."

"Overall over the next few weeks we will have periods that are summer-like and periods that may be reminiscent of May."

Rainfall in the capital was expected to be near normal (at 45 per cent chance), with soil moisture and river flow also near average.

The month of May was known for high rainfall throughout the country, and Noll said they would be keeping an eye on this later in the season.

"The autumn season can bring its fair share of rain-makers to Wellington overall and it is looking like the short-term period will come with some rain, although there's nothing on the immediate horizon in terms of flooding."

The rest of New Zealand followed a similar pattern throughout autumn, Noll said, with periods of warmth interrupted by cold snaps.

"One of the hallmarks of this autumn will probably be the variability," he said.

But some parts of the country were expected to have a wetter season, including drought-affected areas such as Auckland and Northland.