Whanganui weather: Patches of rain and best time to see Puanga

Puanga - the bright star at top left, also known as Rigel - is in the Orion constellation.Image / Supplied

The best times to spot Puanga and Matariki in Whanganui this weekend will be early morning on Friday and Saturday.

Niwa meteorologists said partial to mostly clear skies were expected for Friday morning prior to sunrise, with partial clouds later.

For Saturday morning Niwa reported isolated clear breaks possible prior to sunrise to see Puanga and Matariki.

MetService meteorologist Kyle Lee said the likelihood of seeing Puanga and Matariki depended on the cloud coverage at the time of viewing, which could change quickly.

He said Whanganui's city temperature gauge reached 1.4C early Wednesday morning, which was more than five degrees below the average temperature for this time of year.

"I think generally over the country it's been one of the coldest starts we've had this year."

Lee said Whanganui residents should expect a 3C low overnight on Thursday.

"There is a possibility of frost on Friday morning because of the really cold air mass across the country at the moment.

"During the second half of Friday Whanganui will start to get a northerly wind developing, but otherwise looking fine with a maximum temperature of 17 degrees."

Going into the weekend Lee said the evenings would warm up quite a bit, with an overnight low on Friday night of 8C and 10C the following night.

He said a front would move over Whanganui on the weekend.

"The rain would likely clear towards Saturday afternoon, with patches of rain in the evening."

He said Whanganui residents should expect partial cloud with a few showers on Sunday, and a high of 18C.