Lightning vs. Thunder: What's the Difference?
Read the comparison below, or explore it visually. Create a visual lesson comparing lightning and thunder using available credits or plan allowance.
They're two parts of the same event — one you see, one you hear. Lightning is the brilliant flash of electricity that leaps from a storm cloud. Thunder is the sound created when that bolt superheats the air, making it expand explosively. So lightning comes first and causes thunder; you see the flash almost instantly, then hear the rumble a moment later because light travels far faster than sound.
At a glance
| Lightning | Thunder | |
|---|---|---|
| What it is | A flash of electricity | The sound of that flash |
| Sense | You see it | You hear it |
| Which comes first | First — the cause | After — the effect |
| Travels at | Speed of light (instant) | Speed of sound (~3s per km) |
| Danger | Can strike and injure directly | Harmless sound (but warns of lightning) |
Which should you use?
It's lightning when you mean the visible electric flash — the bolt itself, which can strike the ground.
It's thunder when you mean the sound — the crack or rumble that follows, made by the lightning heating the air.