Bring out the brollies for Christmas Day

Most of the country is in for unsettled, cooler weather on Christmas Day as a wet front makes its way up the country.

Auckland has mostly fine weather in the coming week, with the exception of Christmas Day when rain arrives.

The sun is due to return on Boxing Day, according to a MetService spokeswoman. Forecast highs for Auckland reach about 22C.

Today would be generally fine for most places, although the wind would pick up in Wellington, MetService forecaster Ian Gall said.

A trough moving in from the Tasman Sea would start to produce rain in the deep south late today, which would move up the West Coast tomorrow bringing heavy showers.

The front was expected to sit near the middle of the country by midnight tomorrow before sweeping over the North Island on Christmas Day.

"It's quite a patchy affair.

"It's just going to be quite an unsettled day with most people seeing some rain at some stage," Mr Gall said.

"But at least the front moves through pretty quickly over the North Island on Christmas Day ... and some places will get fine spells."

Accompanying the rain, southwesterly winds would bring cooler temperatures for most of the country, which has so far enjoyed a warm December.

"It won't be cold but there will be a noticeable cooling when the front goes past," Mr Gall said.

"The winds will be changing pretty readily on Tuesday over the South Island to the cooler southwesterlies and it'll happen over the North Island on Christmas Day."

Holidaymakers won't escape the rain either - most destinations in the North Island are set for a soaking some time during the Christmas week.

Between Whangarei and Hawkes Bay temperatures will be warm and hardly dipping below 20C. But rain will fall in most areas over the next four days.