Weather: Road warnings as overnight temperatures set to drop into negatives

It'll be a cold morning for many New Zealanders on Wednesday as temperatures drop into the negatives for some.

A cold front is moving over the country on Wednesday and Thursday morning, bringing snow to low levels, especially in the south and east. MetService said it'll be cold and frosty, with temperatures in parts of Auckland expected to drop to 6C on Tuesday night, along with 3C in Wellington, and -2C in Christchurch.

As well as the cold, snow is forecast to run northwards across the South Island. MetService said the heaviest snow will be north of Arthur's Pass and south of Ward above 300 metres.

There are a number of heavy snow warnings and watches for the South Island as the cold front moves in.

There's a warning for inland Canterbury about and north of Arthur's Pass, Marlborough south of Ward, and Nelson Lakes National Park from 6pm on Wednesday until 8am on Thursday. MetService said heavy snow may disrupt travel in affected areas and could damage trees and powerlines. The cold conditions may also cause stress for livestock.

Heavy snow watches are in place for Buller and western parts of Tasman, inland Canterbury south of Arthur's Pass, Otago south of a line from Queenstown to Mosgiel, Fiordland, and Southland.

Waka Kotahi is urging drivers who need to use roads in Southland, Otago, and Canterbury in the coming two days to be ready for changeable and snowy winter weather.

Nicole Felts, the journey manager for Waka Kotahi in Southland and Otago, said drivers should slow down and be ready for ice in shady spots and on bridge decks, and try to avoid sharp braking.

"Waka Kotahi crews will be busy gritting places which get icy, applying de-icing compound and clearing any snow as quickly as they can. If in doubt we will close highways until they are safe to use so please check our highway map before you set off."

Waka Kotahi's tips for driving on slippery roads are:

  • Drive slower than you normally would - it only takes a split second to lose control in wet or icy conditions
  • Avoid sudden braking or turning movements that could cause you to skid
  • For vehicles without anti-skid braking systems, to avoid skidding or sliding, smoothly pump the brake pedal in short bursts rather than pressing long and hard
  • Drive at a safe travelling distance because it takes longer to stop on slippery roads. In winter, double the two-second rule and leave a safe distance between you and the vehicle ahead
  • When travelling in fog, rain or snow, drive with your lights dipped
  • Makes sure everyone is wearing their seat belt throughout the full journey.