Stunning week of summer ahead for Whanganui

Fine weather is expected in Whanganui this week. Photo / Bevan Conley

After a wet start to summer, Whanganui begins January 2022 with a week of fine weather and light winds.

"There's not too much moving into the Whanganui region over the next week or so," MetService meteorologist Mmathapelo Makgabutlane said.

Temperatures are expected to range from 26C to 28C at the start of the week. Later the winds will change to south and southeast, and the highs will drop slightly to 23C to 25C.

If there is any rain, it could be a shower on Wednesday, January 5, and most likely inland. There will be a bit of cloud in the area on Thursday, January 6.

All the winds will be light, with afternoon sea breezes most days. Seas will be fairly light, with westerly swell at times.

The sea's water will also be warmer. There's a marine heatwave happening around New Zealand, Niwa forecaster Nava Fedaeff said, with water up to 4C warmer than usual.

The heatwave is caused by La Nina conditions in the Pacific, bringing subtropical northeast winds and high air pressure.

It's also cyclone season and tropical cyclone Seth is just off eastern Australia, Makgabutlane said. It's a Category 1 cyclone with a low pressure system, but not expected to affect New Zealand.

The country is in a big high pressure system, with a ridge extending over the country at this latitude.

Farmers and gardeners won't forget there was a wetter than usual start to summer this year. Whanganui's average December rainfall is 68mm, Makgabutlane said, but last month 182mm was recorded at Whanganui Airport.

More than 100mm of that fell between December 12 and 16, with a further 48mm recorded at the airport on December 28.

Whanganui's average annual rainfall is 950mm and 2021's was close to that at 1012mm.

Niwa said 2021 had more than the usual amount of extreme weather around New Zealand.

There were 60 severe weather events and three of them went to the most significant red warning level.

They included high-intensity rains in Canterbury, Gisborne and the West Coast, a tornado in Auckland and record-breaking high temperatures. Christchurch got to 37C and Ashburton to 39C.