“It’s a very warm one coming through.”
For Monday and Tuesday, temperatures were sitting at about 21C and were not expected to drop drastically.
Cloudier weather was coming on Tuesday with continuing mild temperatures.
Law said it was important to keep a close eye on Wednesday as heavy rainfall moved across the country.
“It’s coming from the north and the west, so you’ve got a bit of protection from the hills.”
Thursday was looking to be a wet day with blustery, northwesterly winds also making an impact.
“Particularly, Thursday morning is looking to be the windiest and wettest time in Whanganui.
“The winds can sometimes pick up and come down the hill and squeeze through Whanganui.”
The heaviest rainfall was expected to “slightly miss Whanganui by falling either side of the city” towards the Cook Strait and over Taranaki, he said.
“I think it starts off well for the school holidays but Thursday is the day to be planning your indoor activities.
“Hopefully for Whanganui, we’ll find the worst of the weather clears through pretty quickly.”
The end of the week was much less settled than the beginning, he said.
Law said the worst of the wet weather was expected to hit Taranaki and up over the high country towards the north of Whanganui.
Severe weather alerts have been issued for some parts of the South Island as wet weather takes hold in the latter half of the week.
Eva de Jong is a reporter for the Whanganui Chronicle covering health stories and general news. She began as a reporter in 2023.