Christmas Day weather: Rain and cloud for South Island

Expect a damp Christmas if you are in the south. Photo / 123RF

South Islanders should buckle down for a gloomy Christmas this year, with rain and wind expected throughout the day.

MetService is forecasting a high of 16C in Christchurch on December 25.

Meteorologist Lewis Ferris said the rain will start in the morning and persist into the evening.

"Southerly winds will turn to northeasterly in the afternoon. It is not going to be a great day for Cantabrians."

It will follow a dreary week in the garden city, with rain showers expected each day.

Niwa reported the high of 16C on Monday was 20C colder than it was in 2015.

About 20 degrees colder in Christchurch today than in 2015 😬 pic.twitter.com/4aRueJsoLc

— NIWA Weather (@NiwaWeather) December 20, 2020

It is expected to be much of the same further south, with Dunedin reaching temperatures of 17C.

"There will be cloud periods throughout the day with southerly winds. Some wet weather is looking more likely in the afternoon."

Temperatures are expected to also reach 16C in Timaru, 17C in Queenstown, and 18C in Wanaka.

The further north of Christchurch, the better MetService is forecasting the weather will be.

Temperatures are expected to reach 20C in Blenheim and 22C in Nelson, which will be mainly fine with light winds.

Forecasts suggest Nelson will be the sunniest place to be while Invercargill will be the wettest, with a high of 15C.

MetService data shows this year's Christmas weather is an outlier compared to that of the past 10 years.

Rain, such as what is expected on Friday, has not been seen on Christmas Day in Christchurch since 2013.

Photo / Metservice

The gloomy weather will continue into Boxing Day, with cold southerlies forecast in the morning in Christchurch.

"Those southerlies will just add to the wind chill so again the weather is not looking to be that great."

MetService is predicting a relatively settled Christmas Day for most other places throughout the country.

Tropical Cyclone Yasa, a former category 5 system that devastated parts of Fiji and killed four people, has now been downgraded to an ex-tropical cyclone as it moves south of Tonga.

At one stage it looked to be tracking for a direct hit over the North Island but, thanks to a mighty ridge of high pressure this week, the system has weakened substantially and any remnants are looking to track southeast of the country.

However, two low-pressure systems are forecast to arrive in the coming days from across the Tasman Sea.

While they are not linked to Yasa, they will bring warm tropical air from the northwest, meaning plenty of moisture for the West Coast of the South Island.