Whanganui weather: How long will the chill stick around?

The Whanganui region can look forward to a warmer week as the Antarctic blast departs and a warmer front moves in across the Tasman. Photo / Bevan Conley

The strong southwesterly winds that have been battering the Whanganui region are due to depart on Monday night, taking the rain and snow with them.

Tuesday's forecast is for a fine day with the temperature climbing to a high of 15C with a few southwesterly breezes and an overnight low of 8C.

MetService meteorologist Stephen Glassey said the polar storm that affected most parts of the country on Sunday night and Monday was caused by a significant low-pressure system that has brought southerly gales, rain, and snow.

"The low dragged up cold air all the way from Antarctica," he said.

A high of 16C is forecast for the Whanganui region on Wednesday, and it will be cloudy with the likelihood of showers and an overnight low of 8C.

Thursday's forecast is for cloudy weather and a northwesterly change with a high of 17C and an overnight low of 10C.

A new front moving onto the North Island on Friday will bring early rain, turning to the odd shower and gradually clearing and a high of 16C with an overnight low of 8C.

"The front, preceded by strong northwesterlies, will bring a period of rain as it moves north," Glassey said.

"This next weather system will be completely different to the one affecting New Zealand [on Monday].

"Instead of air coming from Antarctica, most of the air will be coming from Australia, so it will be comparatively warmer, and snow is not expected to be a factor like it is with the current weather system."

Warmer temperatures remain for the weekend, although there are likely to be some showers on both days.

Saturday is forecast to start out fine with showers developing and strengthening westerlies, reaching a high of 16C and an overnight low of 8C.

And the region is likely to see a few showers on Sunday with the high expected to reach 15C and drop to 9C overnight.