“It will be fine in the morning before becoming cloudy in the afternoon and there is the possibility of a few spots of rain in the afternoon,” he said.
“The night temperatures will be warm with a low of 16C overnight on Wednesday and those warm night temperatures are expected to continue for the next few days.”
Rain is forecast for Thursday morning, with showers expected to ease in the afternoon.
There will be light easterly winds with a high of 24C.
A high of 27C is expected on Friday with showers and light winds.
On Saturday, Whanganui can expect occasional rain, likely to become persistent later in the day, and a southeasterly change is forecast with a high of 24C.
There will be showers and southeasterlies again on Sunday with a high of 22C forecast and an overnight low of 15C.
“The winds are not likely to be very strong in Whanganui,” Law said.
“I would suggest that if people are travelling to areas like Taranaki they should be aware that winds are likely to be quite strong. Even parts of South Taranaki will be quite blustery so people should be aware of that when they set out.
“It pays to check the forecast every day because these are conditions that can change quite quickly.”
Whanganui currently has a moderate fire danger rating and Fire and Emergency New Zealand recommends visiting checkitsalright.nz before lighting outdoor fires.
