"Rather than base your plans on a forecast 10 days out, I think it's best to hold fire and keep an eye on the forecast more than anything else."
Mr Law said the broad pattern showed an area of high pressure coming from the east coast of the country. Where that high ended up would influence the variation of weather across the country on Christmas Day.
"There could be a fair bit of moisture and cloud lingering with this [high] so it could be that we are going to find a bit more cloud, particularly for the western side of the country and perhaps towards the north as well.
"There is still so much time for that to change -- I wouldn't let it ruin your plans just yet, it really is going to be a case of checking the forecast."
Mr Law said it was still too early to say what areas would get the best weather this Christmas.
However, WeatherWatch head analyst Philip Duncan said those inland -- such as Queenstown, Rotorua and Taupo -- had the best chance of sunny weather this Christmas Day.
"We won't know until Friday with real accuracy, but I can tell you that if this high does come in, then the best places to be will be inland areas."
Mr Duncan said a high pressure system would start to move in early next week.
"We will have an unsettled start to next week -- it's going to be wet and a bit windy for some areas.
"Hopefully just before Christmas Day a nice big high from Tasmania will slide in and settle the weather down."
He said while it may not be "perfectly sunny or overly hot", more places would be dry rather than wet.
Christmas Day forecast:
Whangarei -- Rain. Easterlies. High 22C, Low 18C.
Auckland -- Showers. Northeasterlies. High 21C, Low 16C.
Tauranga -- Rain. Northeasterlies. High 21C, Low 16C.
Hamilton -- Rain with light winds. High 22C, Low 15C.
Wellington -- Partly cloudy. Northeasterlies. High 17,C Low 15C.
Christchurch -- Partly cloudy. Easterlies. High 23C, Low 13C.
Dunedin -- Partly cloudy. Easterlies. High 16C, Low 12C.
(Source: MetService)
