Waitemata Harbour in Auckland. Photo: Supplied
Humidity for the upper North Island is here to stay a little while longer - but there will be some relief during the night.
MetService meteorologist Dan Corrigan said a low pressure system across the Tasman Sea was creating a lot of moisture and bringing the humid air to much of the upper North Island, including Auckland.
The humid air was expected to continue through to Christmas, although it would not be as severe as what had been experienced on Thursday, Friday and Saturday, he said.
Where overnight lows in Auckland were as high as 20C, Corrigan said this week would see temperatures drop overnight to around 15C or 16C.
Thursday would see a "bit of a change" in the air, Corrigan said, but the humidity would still be hanging around.
"It's just how Auckland is at this time of year. We see warm days and warm nights."
With the heat setting in around the afternoon, Corrigan said this was the time people could expect to see some changes in the weather today.
Shower clouds and thunderstorms started "bubbling up" and there was a risk people in the central North Island may see some this afternoon/evening.
Corrigan said it would not affect all areas, as the weather would be very localised but thunderstorms were possible.
As of Thursday, MetService was predicting the weather would be nice to Kiwis on Christmas Day.
Meteorologist Tui McInnes said: "Weather models are indicating high pressure around or over our shores on the 24/25 December.
"This is a good sign, as it will generally keep any of the widespread rain makers away, but that doesn't rule out any of those afternoon heat showers popping up.
"There's still a chance of rain affecting some regions and MetService will be able to give you more detail on that as we get closer to the day."
As of today, MetService's extended forecast only shows as far as Friday where it predicted isolated showers for most parts of the country.
Short Forecast
Northland, Auckland, Waikato and Waitomo, also Coromandel
Fine spells and a few showers, some may be heavy this afternoon and evening, with possible thunderstorms about Northland.
The remainder of the North Island, also Marlborough and Nelson
Partly cloudy with scattered showers, some heavy with possible thunderstorms this afternoon and evening, especially inland.
Buller and Westland
Showers, some heavy and possibly thundery.
Canterbury
Mostly cloudy at first with areas of rain. Rain clearing by midday and fine breaks developing. However, isolated showers this afternoon and evening, some possibly heavy inland.
Otago, Southland and Fiordland
Some cloudy areas. Isolated showers, mainly from afternoon, then rain in the far south tonight.
Chatham Islands
Mostly cloudy. Occasional rain, clearing this evening.