Transpower is investigating power outages that affected its grid from Timaru through to the top of the South Island.
A spokesperson said it may take up to another hour for it to be restored.
More than 50,000 customers across Christchurch and Banks Peninsula had been without power, Lines company Orion said, but it has since been restored.
Hurunui District Council said power is also now back on in the district.
Mainpower said it is in the process of being restored in Kaikōura.
An Orion spokesperson said it is due to an issue with the Transpower line coming into the city from Twizel and it is working with them to restore power as soon as possible.
