Why you shouldn't shower during a thunderstorm

Aucklanders staying indoors to avoid Thursday night's lightning might have been making an equally grave mistake, if they stayed warm by hopping in the shower.

There were more than 700 flashes during the storm, four of which hit the Sky Tower.

The iconic tower is earthed of course, unlike some people's home plumbing and electrical systems. It's a little-known fact that washing your hands or getting in the shower during a storm can be fatal.

Meteorologists in the US say between 10 and 20 Americans every year are shocked by lightning that's reached them through faucets, and the UK's Met Office has warned residents there to avoid running water altogether.

It sounds like a myth, which is why in 2005 the hosts of TV show MythBusters put it to the test. Although their test dummy wasn't hit by a fatal current, a small fire broke out, and they rated the myth "plausible".

They also tested the advice to avoid using landlines during a storm (it was 2005, so not that outlandish a scenario). The bolt leapt out of the phone into the dummy's mouth, confirming it was a good idea.

Other things to avoid during a thunderstorm, according to experts, are washing machines, basins windows, doors, trees, fences, clotheslines, computers (if they're plugged in) and metal pipes.

In June, five people were killed when lightning struck a swimming pool.

Contrary to popular belief, most people who are struck by lightning survive.