Niwa is predicting a drier than normal spring for all the North Island, and for the north and east of the South Island.

While several regions may have unusually long dry spells at times during the next three months, rainfall could be normal or even above normal in the north and east of the North Island for the next couple of weeks.

Spring was expected to be windier than normal, particularly when westerlies intensified, as was predicted from the second half of September, Niwa said in its Seasonal Climate Outlook, published on Friday.

For the weekend, MetService forecast a mainly dry Saturday across the North Island, but with isolated showers turning to rain in Northland at night.

The rain was expected to spread south on Sunday, with some heavy falls possible in the north and east of the North Island. For Auckland, easterlies are forecast to become strong in the morning on Sunday, while rain is expected to become persistent in the afternoon.

A dry weekend is forecast for Wellington, with plenty of sunshine.

Much of the South Island is expected to be mostly dry on Saturday, with drizzle in the Canterbury foothills in the afternoon. Sunday is also expected to be mostly dry, with isolated showers in the far south and occasional light rain or drizzle for Canterbury and Otago.

A sunny start to Saturday is forecast for Christchurch, becoming cloudy in the afternoon, and with areas of fog developing in the evening. Sunday is expected to be cloudy with easterlies developing.

Niwa’s climate outlook predicted more southwesterly winds than normal across the country for spring as a whole. That would result from above normal air pressure to the northwest of the country, and below normal air pressure to the south.

That pattern was not expected to apply in the next couple of weeks, when more easterlies were expected, Niwa said.

Occasional outbreaks of cold air were expected, as well as episodes of warm to hot air from Australia, particularly in the east of both islands.

“A prevailing area of high pressure near the North Island may lead to clear, cold nights and mornings and the potential for unseasonable frosts,” Niwa said.

Soils were expected to be drier than normal in the north and east of the North Island, near normal in the South Island, and near or below normal in the west of the North Island.

More westerly quarter winds and frequent lows and fronts were expected to be driven into the western and lower South Island, wetting up western areas of the South Island, in particular, from the second half of September.