Some residents across the Queenstown region have only just regained power after a violent thunderstorm early this morning.

More than 12,000 customers in Queenstown, Frankton and Arrowtown woke up to darkness after lightning struck an Aurora Energy grid exit point.

Queenstown's Lakes District Hospital was forced to use a backup generator, and the road to Glenorchy was closed for the day after the storm ripped through, covering it in debris from a slip.

MetService said there were 286 lightning strikes over the South Island in a three hour period.

One resident who was particularly rattled by the storm was Saxon the dog, who ran off.

Max Towle spoke to his owner Athena Turner about how it unfolded.