Science Common Sense

23 - What causes lightning?

Lightning is caused by electricity in the air. It happens when there's a big storm with tall, fluffy clouds called thunderstorm clouds. Inside these clouds, tiny ice and water droplets rub against each other, creating static electricity.

This electricity builds up until it's so strong that it breaks through the air as a bright, hot bolt of lightning. That's why you see a flash of light in the sky during a thunderstorm.