Maniototo farmer Phil Smith said five ewes and seven lambs were sheltering under a tree on his property when it was struck by lightning on January 6, killing them instantly.
He said he had heard of it happening on other farms around New Zealand, but it was the first time he had seen it happen on his farm.
"I didn’t know it had happened for the first few days. I only got notified by my neighbour. She walked her dogs down the road and she came across them and rung me about it.
"You don’t like any stock dying, but what can you do. It’s happened and you just have to deal with it and carry on."
Photos of the dead sheep around the tree were posted to social media.
Many commented about similar incidents where stock and people had been struck by lightning over the years, while others expressed surprise at the level of damage a single lightning bolt could deliver.
"Pretty horrifying and amazing at the same time," one person said.
Statistics show lightning strikes the ground in New Zealand about 190,000 times a year, and the chances of being struck by it are about one-in-280,000 — lower than most other countries.
MetService meteorologist Lewis Ferris said there were nearly 670 lightning strikes around Otago and Southland on January 5 and 6 alone.
"January 5 and 6 were pretty active, and so far this year there has been 1272 strikes around Otago and Southland."
He said lightning strikes generally happened in summer when daytime convection was most likely.
Being outdoors was not a good idea in thunderstorms, he said.
"There’s a famous saying — when thunder roars, go indoors.
"Do not shelter beneath trees or any tall structure, especially if it’s metallic."
