Weather: Christmas Day to bring sunshine for some, rain for others

As Kiwis across the country prepare to ease into their summer holidays, many will be hoping Santa brings them sunny skies and warm temperatures for Christmas Day.

And though it's looking like that will be the case in some parts of the country, not everyone will be so lucky.

According to NIWA, Christmas Day is shaping up to be mostly fine across northern and central New Zealand, but southerly winds are forecast to bring unsettled and cooler conditions down south.

The cold southerlies will spread over the remainder of the country during the weekend, bringing rain or showers to easterly areas, and unseasonably cold temperatures to southern and central New Zealand.

"For most of us the weather leading up to Christmas Day is not ideal for completing that final bit of gardening or tidying up outdoors, and folk with kids on holiday will need to plan some indoor activities," MetService meteorologist Peter Little said on Wednesday.

A trough of low pressure moving across the country was set to bring rain to much of southern and central parts of the country on Wednesday and Thursday, with a period of strong northerly winds also forecast for exposed parts of central New Zealand, Little said.

A south to southwest flow is set to cover much of the country on Christmas Day, bringing generally settled and warm weather to northern and central parts of the country. However, another trough is forecast to move onto southern New Zealand from the Tasman Sea, with showers and cooler temperatures on the way for eastern areas.

Mostly sunny skies are forecast for Auckland, Hamilton and Tauranga, with daytime temperatures expected to reach into the early to mid-twenties. Wellington is looking at cloudy periods, dying southerly winds and a high of 19C, while Christchurch and Dunedin are set for mostly cloudy skies with a few showers and a high of just 16C on Christmas Day.

"Although the forecast is dry for much of the country on Christmas Day, there will be some places that get rain or showers, especially in the south," said Little. 

The trough will bring cooler southerly winds as it moves over the remainder of the country on Boxing Day, with rain or showers likely in eastern areas of the country, and "unseasonably cold temperatures to many places".

The weekend will bring snow down to 1000 metres in some parts of the South Island, with Ashburton set to have a high of just 13C on Saturday - around 8C below average for this time of the year, Little said.