"On Sunday there will be low cloud in the morning with a few light showers. It might be a little bit drizzly if you get further up in the ranges and then clearing in the afternoon. All the cloud will return in the evening and we're looking at light winds that day."
Ms Clark said the "unusual" easterly winds meant the region, like much of the eastern part of the country, was being cooled down.
"For New Zealand normally the predominating flow is westerly and that's the reason why the eastern coast is a lot drier than the west.
"It means we're sheltered by the ranges but it's the opposite right now. We're got easterlies so the ranges on the east coast are sheltering the west coast rather than the other way around."
Clouds would also take longer to break up in the morning, meaning the land wouldn't heat up as fast as it had earlier this month, the meteorologist said.
"It's just that change in wind direction and with quite a lot of moisture around at low levels there's more cloud so that's the reason there are lower maximum temperatures over the weekend."
While temperatures were lower than much of last week, which saw highs of 30C, it would still feel very warm, she said.
"Hawke's Bay has the same air mass as Auckland so it is feeling a bit more humid than it normally does. They are lower temperatures but it may feel more sticky at night during January."
Humid conditions were expected to persist with temperatures hovering at the high 20s in the coming week, which was forecast to end with rain on Friday.
