Why do you see lightning before hearing thunder?

When lightning strikes, it produces light that travels at an incredible speed of about 299,792 kilometers per second (186,282 miles per second). This is much faster than the sound produced by the thunder, which travels at approximately 343 meters per second (1,125 feet per second) in air. Therefore, you see the flash of lightning almost instantaneously, while the rumble of thunder takes a bit longer to reach your ears, leading to the classic “lightning before thunder” phenomenon.

Now, how far away is that storm? A fun trick to gauge the distance of a thunderstorm is to count the seconds between seeing the lightning and hearing the thunder. For every five seconds you count, the storm is roughly one mile away! So, next time a storm rolls in, count carefully—it’s an exciting way to stay safe and engaged!