What Causes the ‘Sound’ of a Thunderclap?

Thunderclap sounds like a loud boom because lightning heats up the air around it really quickly. This makes the air expand and push against the air next to it, creating a sound wave that travels to your ears. It’s like when you blow on a hot soup, the steam goes whoosh! and makes noise.

When lightning happens, it can be really hot, as hot as 30,000°C! That heat makes the air around the lightning expand in an instant. This sudden expansion causes the air to move quickly, making a big boom that you hear as thunder.

Sometimes thunder sounds far away because the sound wave takes time to reach you. The louder the boom, the closer it is, just like how your voice sounds bigger when you’re right next to someone.