Rain is heading New Zealand’s way for the last working week of the year, with some parts of the country in for heavy rainfalls ahead of Christmas.

And whether or not Christmas Day will be a barbecue at the beach or lunch inside will be better known next week, as forecasters keep a close eye on the skies and what we can expect for Christmas.

‘Make a back-up plan’

The whole of New Zealand is basking in sunshine this weekend, with temperature highs in the late-teens or early 20Cs for most.

However, rain is on the cards for next week and MetService says although it is still a little early to forecast what the weather will be like on Christmas Day, we could be in for some rain on the big day.

MetService meteorologist Silvia Martino said: “Definitely, at this point, it’s looking changeable enough to say: ‘Maybe make a back-up plan’.

“We do have some extended forecasts ... but 10 days is the furthest it takes you to.

“Even within that time, we could get a lot of changeability and further out than that, you do have the risk that things will swing out wildly.”

Haydn Reardon gets into the spirit of the season as he takes to the surf at Mount Maunganui in December 2015. Photo / Alan Gibson

Auckland is in for another mainly fine day tomorrow, apart from a few showers north of the Harbour Bridge in the morning and later in the evening.

A temperature high of 25C and overnight low of 16C is forecast for the City of Sails tomorrow.

Martino said next week would bring “slightly more dramatic” weather.

“We do have some weather rolling through from the west ... moving reasonably quickly. It is bringing some heavy rain to the South Island and then some more rain on to the North Island.

“That could hang around for a few days in the middle of the week,” she said.

“So there is a possibility that yes, some places might have a bit of a sad week this week coming up - it will stay wet for them for a few days.”

Monday is set to be a fine day in the east and south of the North Island. However, it will be partly cloudy with isolated showers in the north and west.

Those in the South Island can expect rain, with heavy falls developing in the west and south. It will likely be partly cloudy in the north and east.

MetService says rain will develop in the west of the North Island on Tuesday, with some heavy falls. Gisborne and Hawke’s Bay look like the places to be, though, as fine skies are forecast for the day.

The South Island is in for rain in the north and west, with heavy falls also on the forecast. It will likely be partly cloudy elsewhere, with some showers.

Martino said there was also a risk of severe weather for some areas in the South Island, particularly around Fiordland.

“Just whether it reaches warning amounts away from the ranges, that’s the question there.

“I hope that after that, things clear out enough to have some nice days in the lead-up to Christmas.”