Whanganui will have a brief respite from rainy skies on Saturday, before the gloom is predicted to descend on Sunday and remain in place into the start of next week.
MetService meteorologist April Clark said a low pressure system was set to come in from the Tasman Sea, but it would remain "relatively dry" on Saturday.
"No one will escape the rain for the whole weekend though, unfortunately," Clark said.
"It'll be progressively cloudier throughout the day [Saturday], and it's looking like the rain will be developing overnight."
The low pressure system would move over the whole of the country on Sunday, Clark said, with more bad weather expected for Whanganui.
"Generally it'll be quite a rainy day on Sunday. A southerly will be picking up as well, meaning temperatures will begin to drop.
"Whanganui is looking at a high of 23C on Saturday. It will still be quite humid, and that air mass over the whole of the North Island has been quite sticky.
"On Sunday there'll be a high of 20C but I think in the afternoon there will be a marked drop, and on Monday the daytime temperature will be 14C."
Clarke said the overnight temperature on Saturday would be 14C and Sunday would be 8C.
"Monday is looking like rain and strong southerlies, and Tuesdays will also bring rain as well. That low is obviously not budging.
"Saturday is definitely the day for people to go out."