"There's not a lot of moisture around, so weather tends to be pretty settled under a high pressure system. That's moving away east and all the frontal stuff, which is bringing the rain, is coming in from the Tasman," Bakker said.
"I'd recommend [Aucklanders] get stuff sorted in the morning as the risk of showers increases from afternoon onwards."
Bakker said "it's sort of a pulse of wet weather".
Wellington will have a high of 15C with patchy drizzle in the morning developing into rain at night.
WhangÄrei and Tauranga are forecast for a highs of 18C with the odd shower.
Hamilton, New Plymouth and Christchurch have highs of 17C with a few afternoon and evening showers.
Palmerston North will have a high of 17C, with cloudy but dry conditions.
Rotorua is forecast for a high of 15 with the odd shower.
Dunedin has a high of 13 with occasional rain.