What Causes Lightning

Lightning is electricity jumping between clouds and the ground. That streak of light in the sky? It’s not just a flash — it’s a full-on electrical leap.

Lightning starts with a surprising bit of sky traffic: tiny ice crystals and water droplets bumping into each other inside storm clouds. These collisions cause a buildup of electric charges — kind of like rubbing a balloon on your hair.

Lighter particles float to the top of the cloud with a positive charge, while heavier ones sink to the bottom with a negative charge. The cloud becomes an electric sandwich, just waiting to spark.

Eventually, that charge gets so strong, it leaps — either to another cloud or down to the ground. The result? A lightning bolt that can stretch over five miles long and heat the air around it to 30,000°F — that’s hotter than the surface of the sun.

And get this: a single bolt of lightning carries enough energy to power a house for an entire day. That’s one powerful zap.

Lightning doesn’t always strike in a straight line, either. It darts and forks, looking for the easiest path — and can even strike the same place twice. (The Eiffel Tower, for example, gets hit about 10 times a year.)

So next time you see a flash in the sky, remember: it all started with tiny bits of ice and water playing bumper cars in the clouds.

Try this at home:

Blow up a balloon, rub it on your hair, and stick it to a wall. That’s a mini version of how static electricity builds up — just like it does in a thundercloud!