A flash of light on a grey day. If you're made of metal, you best stay away. What am I?

Answer: lightning

More What am I ? with answers

More What am I ?

A hole in a pole. Though I fill a hole in white, I’m used more b the day and less by the night. What am I?
A house with two occupants, sometimes one, rarely three. Break the walls, eat the borders, then throw away me. What am I?
A king in red with a sole command. If you obey, it will cause you to break. What am I?
A large oasis in the desert. Come with cash and leave with none. What am I?
A long snake that smokes. What am I?
A move made popular b the King of Pop. What am I?
A move made popular by the King of Pop. What am I?
A natural state, I'm sought by all. Go with me and you shall fall. You do me when you spend, and you use me when you eat to no end. What am I?
A necessity to some, a treasure to many, I’m best enjoyed among pleasant company. Some like me hot, some like me cold. Some prefer mild, some like me bold. What am I?
A piece of paper that takes most people 3 or 4 years to get. What am I?
A popular afterlife location to send evil people. What am I?
A pot-hole filled valley, where rains often fall; A land through which no river shall crawl. What am I?