Tuesday's expected temperature is around 18C, with scattered cloud from the afternoon.
"We've got westerlies to northwesterlies that tend to be pretty breezy through Whanganui. We are looking at a strong westerly change on Tuesday evening and that is going to last right till the end of Wednesday."
The temperature drops to around 13C on Wednesday, with showers and strong westerlies expected.
"The rain comes in pulses, it will be very on and off. But there is a band going through on Tuesday afternoon and another one going through around midday on Wednesday which is when the majority of rain will be."
The temperature starts to move up again on Thursday and Friday, climbing up to 16C and 18C, respectively.
Rain is expected to ease over the two days, before another pulse hits on Saturday.
Rain looks to dissipate on Saturday afternoon, with Sunday looking to be a bit cloudy and a high of 17C.