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Last Updated: Thursday April 07 2011 10:43 GMT

Thunderstorm fact file!

Thunderstorm in the south of England

Wild weather! Check out these amazing pics of thunderstorms from around the world...

Thunderstorm over a circus ground

They're caused by a quick rush of hot moist air which rises up into the atmosphere. As the warm air gets higher it cools down and forms a massive cloud.

Three people watch a lightning bolt from a distance

Weather experts call this type of storm cloud a cumulonimbus - you can usually spot one brewing as they're pretty big!

Storm cloud

Thunderstorms get their name from the rumble that you can hear when lightning strikes - sometimes it sounds like loud clap or crack.

Lightening strikes a mountain

The noise is caused by the formation of lightning, a bolt of bright electricity that you can see in the sky.

Lightening strikes a mountain

Lightning can travel really fast - up to a mega 140,000 miles an hour! Speedy!

Lightning storm over San Francisco

And it's not only fast: each bolt can contain up to one billion volts of electricity and can be up to five times hotter than the surface of the sun.

Storm cloud

It's no surprise that the flashes can be dangerous - each year around 2000 people around the world are killed after being hit by a lightning bolt.