Whanganui weather: Wet and humid days set to ease, fine weekend ahead

The rain brought debris down the Whanganui River. Photo / Bevan Conley

Despite a heavy rain warning in place over Wednesday night, moisture was more prominent in the air than on the ground as Whanganui missed most of the rain but soaked up plenty of hot, humid air.

A severe weather warning was issued for Whanganui on Wednesday, with Metservice warning of possible downpours up to a total of 140mm and the threat of surface flooding and slips.

However, Metservice said most of the rain fell either off the coast or further north.

"The models had that rain farther north than what it was in reality, so there was plenty of stuff out in the South Taranaki bight, but in Whanganui itself not so much," meteorologist Andrew James said.

James said that 18mm of rain was recorded at Whanganui Airport, the city's main weather station, over the past 24 hours.

"There wasn't as much rain there as expected. There will be a small amount hanging around this afternoon, and then things do start to clear up after that."

Despite the severe rain not coming to fruition, the weather was certainly still noticeable last night, with temperatures barely dropping, hitting a low of just 17.9C.

"We have air that's been dragged down from North Queensland by a low-pressure system," James said.

"Warm air holds a lot of moisture, so it's been feeling very muggy and very damp and has been a bit of a struggle to get some sleep overnight."

According to Metservice, the low-pressure system is set to move away today, paving the way for slightly cooler temperatures and clearer days.

"This system will move off today and this rain eases, and then a front will move up from the South for a cooler, dryer airmass. In the coming days, its looking like things will be looking a decent bit cooler."

Friday, Saturday and Sunday are looking fine, with some cloud hanging over the city. Tomorrow's high is 21C, dropping to 19C on Saturday.