Weather: Temperatures plunge to -10C in the south

Winter is biting a few days early in the south with temperatures plunging as low as -10C overnight.

Local forecaster Mackenzie Country Weather NZ says it's a "bone cold" morning in the Canterbury High Country. Many areas were well in the negatives on Wednesday morning; Fairlie being the coldest at -10C while Tekapo remained at -8C at 7am. 

MetService meteorologist Ashlee Parkes says many other areas also fell well into the negatives.

"Dunedin Airport was -7.1C, Mt Cook was -6.4C; even Timaru Airport was -7.8C so it has been a very cold morning for [the] central and southern South Island," she told Newshub.

Further up the South Island, Christchurch fell to an overnight low of -3.1C.

It was cold in the North Island too with some areas also dropping into the negatives, according to MetService. Taumarunui in the central North Island also dived to -3.1C.

Looking ahead, Thursday won't be quite as cold to start the day with a low of 2C expected in Christchurch overnight, 4C in Dunedin, 7C in Wellington, 5C in Hamilton, and 9C in Auckland.

But there'll be a "big low" moving across New Zealand at the weekend. Parts of the South Island, including Canterbury, have been told to expect severe and wintry weather.

"Rain in the east of the South Island may be heavy too. Some early estimates… show 70 to 90mm possible through inland Canterbury on the plains," WeatherWatch said in a statement. 

"The North Island has milder westerlies until the colder southerlies kick in later Sunday and into next Monday."