An aurora lit up skies at the southern end of the country overnight.

Stargazers took to social media to post their photographs from places like Dunedin, Waihola Lake, Roxburgh, Cromwell and Mount Cook.

Te Whatu Stardome astronomer Josh Aoraki in October told RNZ aurora could often be caught on camera, even when they were not visible to the naked eye.

Aurora over Dunedin and surrounding areas. Photo: Jennifer Gould, Dunedin

"We're currently in a pretty high activity period with our sun, and the aurora is a direct result of solar activity interacting with the Earth's magnetic field."

The further south you went - place like Twizel, Southland and Otago - the better the view. Spots with less light pollution worked best.

He said aurora were notoriously hard to predict in terms of how bright they would be, but people could keep an eye on the space weather forecast on the NOAA website.

Meanwhile, Transpower has lifted the grid emergency that was issued on Wednesday afternoon now the G4 geomagnetic storm - the force behind the aurora - had reduced in severity.

It said in a statement the South Island electricity transmission lines, taken offline as a precaution to prevent damage to equipment, had now been returned to service.

There was no impact on consumers' electricity as a result of the storm.

Transpower said this kind of action was standard when space weather reached a particular level.

Aurora colouring the clouds. Photo: Jennifer Gould, Dunedin

A plan had been developed over several years through work with the University of Otago, international space agencies and others in the electricity industry.

Although New Zealand was well prepared for geomagnetic storms, Transpower said, it was a timely reminder to Kiwis that they should be prepared for a natural disaster or other major event that could interrupt their power supply and damage other infrastructure.

Last week, the National Emergency Management Agency and other affected agencies ran through a test scenario of a solar storm response in the Beehive's bunker, to make sure they are adequately prepared.

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