'Significant autumnal change': Wetter, windier weather for South Island this weekend

Heavy rain and strong winds is forecast to lash lower parts of the country this weekend.

MetService said a "significant autumnal change" was expected to arrive in the second half of the week.

It said after a fine Monday and Tuesday, a change in the Tasman Sea was unfolding, with a large area of low pressure set to arrive in New Zealand on Wednesday.

"While we've been enjoying the light winds and lack of rain for the last while, these crisp still mornings are about to end and the wetter side of autumn is set to come back with a bang," MetService meteorologist Braydon White said.

Rain was expected to set in for western areas of the South Island from Wednesday, with a gradual increase in showers for northern parts of both islands.

MetService said it then would spread northeast on Thursday with most areas experiencing rain with western and northern parts receiving "heavier bursts".

"The wetter weather brings along much warmer temperatures," White said.

"Overnight temperatures will be as much as 15°C warmer than we've had recently, with minimums in the mid-to-upper teens widespread across the North Island."

A second, deeper area of low pressure was expected to bring more heavy rain and strong winds for the South Island on Friday.

The system will bring a change to strong southwesterlies as we moved into the weekend, with large swells possible for western coastlines, MetService said.

Sign up for Ngā Pitopito Kōrero, a daily newsletter curated by our editors and delivered straight to your inbox every weekday.