After a week of settled weather over Aotearoa, we head into the start of this week with a change to more Spring-like conditions.

'An active cold front moving up the South Island today is forecast to deliver heavy rain and generate strong winds over many parts of the island," says MetService meteorologist Andy Best.

"The front moves across the North Island on Tuesday with Severe Weather Watches and Orange Warnings in place for many areas as well as the possibility of thunderstorms for parts of the upper North Island. People are advised to go to metservice.com for details on this event.”

In addition to the front affecting the country today and on Tuesday, another front is forecast to move onto the South Island Wednesday morning.

This front is expected to bring much colder weather in its wake, as the freezing levels lower dramatically, bringing a distinct wintery feel to conditions over the far south of the country.

"The origin of the cold air is over southern parts of the Southern Ocean, and as this cold outbreak moves onto the country, we are forecasting snow to around 400 metres over Southland, Fiordland and Otago during Wednesday.

"Road Snow Warnings may be associated with this event, so keep up to date with the latest weather on the MetService website.

'The maximum temperature in Dunedin on Wednesday is expected to be only 9C and just 8C in Invercargill. Temperatures overnight Wednesday/Thursday are expected to fall to 0C in Christchurch and Blenheim, around 2 or 3C in the northern Wellington suburbs and down to 0C at Masterton as the cold air pushes farther north."

The cold southwesterlies are expected to persist over the entire country during Thursday, although the weather over the North Island should become mostly fine.

Because of the southwest direction of the wind flow, the South Island is expected to also experience mostly fine weather on Thursday, apart from just a few showers in the south and west, with snow to 600 metres in the far south at first.