Head south for Christmas sun

The South Island looks like the place to be, with heavy rain possible in parts of the north on Christmas Day.

The culprit: a complex low pressure system moving in from the northwest over the Tasman Sea.

The low, bringing rain with it, will drift slowly towards the upper North Island tomorrow and continue to move southeast on Christmas Day, according to MetService.

Heavy rain watches are in place for Auckland, the Coromandel Peninsula and Northland. Taranaki and Gisborne could also reach warning levels on Christmas day.

MetService duty forecaster Larissa Marintchenko said the low was bringing in warm air – so while it might be wet, it should still be a relatively warm Christmas in the north.

The South Island is set for mostly fine weather for tomorrow and Tuesday.

‘‘I would say the South Island will be pretty beautiful,’’ Marintchenko said. ‘‘I can see temperatures in Central Otago, Alexandra, Wanaka and Queenstown of 27 and 28 degrees.’’

Marintchenko said there was the possibility of showers in Marlborough, and isolated showers were a possibility for Nelson and Buller, likely in inland areas.

The low is forecast to move away from the country on Boxing Day, bringing a ridge of high pressure and warm, clear, sunny conditions from the Tasman for Thursday.

Christchurch Christmas Day forecast is for a cloudy-but-warm 23 degrees.