The country is waking to a bitterly cold morning with temperatures dropping as low as -6C in some areas overnight amid threats of power cuts.

Meanwhile, the group representing big industry is warning that appeals to conserve electricity will become more common.

Electricity grid operator Transpower on Thursday warned the low temperatures could see power cuts occur if electricity demands spiked too high, particularly between the hours of 7am and 9am.

WHAT YOU NEED TO KNOW:

• Transpower has warned households that unless they conserve electricity, they could face possible power cuts on Friday.
• It said households could help by turning off heaters and lights in unused rooms, delaying using appliances, and not charging devices and cars.
• The time of main concern for power shortages was between 7am and 9am on Friday morning.
• New Zealand's largest electricity distributor is warning the country to hurry up with controls around charging electric vehicles or face unnecessary bills running into the billions.
• A group representing big industry is warning that appeals to conserve electricity will become more common.