Whanganui's temperatures will remain in the late teens and early 20s Celsius for the next seven days, with little to no chance of rainfall.
"It's looking pretty good for much of the rest of the week," MetService meteorologist Andy Best said.
"There'll be a few cloudy periods on Tuesday, but we will see some bright spells as well. The maximum [temperature] will be 19 degrees."
High humidity over much of the central and upper North Island were forecast to be the focus of the working week, as a weak low pressure area over the north Tasman Sea drifted towards Aotearoa on Wednesday and Thursday.
Best said the influx of "relatively warm air" from across the Tasman Sea and the sub-tropics meant there wouldn't be any frosts like the one Whanganui had experienced last Thursday morning.