Lightning is one of the most spectacular forces on Earth. A vivid and energetic thunderstorm can strike awe and fear into anyone close enough to experience these intense displays of nature’s raw power. The approach of a thunderstorm is unmistakable—sometimes you even hear the crack of thunder before you see any clouds. But that isn’t always the case. Is it possible to have lightning without hearing any thunder?
Lightning is a static discharge in the atmosphere. Ice crystals and water droplets bouncing around high in a thunderstorm create static electricity that results in different layers of positive and negative electrical charges throughout the clouds and on the ground below. Like all weather events, lightning is just nature’s attempt to balance things out—in this case, it’s trying to balance out an uneven electrical field in the atmosphere.
You can see quite a few different types of lightning during a thunderstorm. The type we’re most familiar with is cloud-to-ground lightning—this can originate from the base of the clouds (negative lightning) or from high up in the thunderstorm (positive lightning). While all lightning is dangerous, positive strikes are the most dangerous because they’re much stronger than negatively charged bolts and they can strike dozens of miles away from a thunderstorm where the skies are clear (a “bolt from the blue”). We also commonly see lightning strike from cloud to cloud, lightning flashes within the same cloud, and lightning that stretches from a cloud to the air around it.
No matter where it originates or what it strikes, lightning is hot; in fact, the average lightning bolt is many times hotter than the surface of the Sun. Even though most bolts only last for a fraction of a second, those extreme temperatures still rapidly heat up the air around the bolt. This superheated air expands out at a rapid pace in the form of a sonic boom, which is the rumble of thunder we hear and sometimes feel. This answers our question: All lightning creates thunder because all lightning is hot enough to create that sonic boom.
But, as always, there’s a catch.
A flash of lightning in a thunderstorm on the horizon. Image credit: snakeyes-man via Flickr // CC BY-NC-ND 2.0
Even though all lightning creates thunder, you can see lightning without hearing thunder. The sound of thunder dissipates as it travels away from the point of the lightning strike, only traveling a dozen miles or so before petering out. You can see the flash of a lightning bolt in a thunderstorm more than 100 miles away from your location. If you have a good view of the horizon on a stormy day, you can see dozens of lightning strikes and flashes in the clouds off in the distance without ever hearing the resulting thunder. This phenomenon is incorrectly called “heat lightning,” as people used to think that it was the hot, muggy air itself causing the lightning instead of a thunderstorm off on the horizon.
The environment around you can also affect how well you hear thunder. Heavy rain or snow can muffle the sound of thunder and reduce how far the sound can travel away from the lightning bolt. Features like mountains, valleys, and buildings can both muffle thunder or cause it to echo loudly. Different layers of air temperatures can even amplify the sound of thunder—a temperature inversion (warm air trapped between two layers of cooler air) that occurs near a thunderstorm can cause a rare phenomenon known as “ducting,” which allows a loud crack of thunder to travel through the inversion for dozens of miles, often scaring people who think they just heard an explosion rather than a thunderstorm many miles away.