Why is Lightning Dangerous?

Question: Why is Lightning Dangerous?

Worldwide, 16 million lightning storms occur every year—2,000 of those storms are happening simultaneously at any given moment—and it's more than just a spectacular natural light show.

Every year, lightning kills roughly 10,000 people around the world (about 90 in the United States) and injures about 100,000 (approximately 400 in the U.S.).

Answer: Lightning is the world's most underrated weather hazard. It's also the most unpredictable.

When it comes to lethal weather, lightning is hard to beat. On average only floods kill more people than lightning. In the United States (and most other places), lightning routinely kills more people every year than tornadoes or hurricanes. Other weather hazards, such as hailstorms and windstorms, aren't even in the running.

One reason lightning is so dangerous is that it's hard to know just when and where it is likely to strike—or how it will behave when it does.

"Lightning is the first thunderstorm hazard to arrive and the last to leave," according to the U.S. National Weather Service. Lightning can actually strike outside the storm that produced it. Although most lightning will strike within 10 miles of its parent thunderstorm, it can strike much farther away. On rare occasions, lightning-detection equipment has recorded lightning striking up to 50 miles away from the thunderstorm.

Another reason lightning is so dangerous is because of the destructive power it carries. The average lightning bolt carries about 30,000 amps of charge, has 100 million volts of electric potential, and is hot, hot, hot at about 50,000 degrees Fahrenheit.

Add up all of these factors, and it's pretty clear that lightning makes every thunderstorm a potential killer, whether the storm produces one lightning bolt or 10,000.

To make matters worse, lightning isn't restricted to thunderstorms. Although you can't have a thunderstorm without lightning—thunder is the sound that lightning makes—you can have lightning without a thunderstorm.

Lightning has been seen during volcanic eruptions and extremely intense forest fires. It has also occurred during hurricanes and heavy snowstorms. Lightning has even been seen during surface nuclear detonations.

Lightning is unpredictable in other ways, too. Lightning can occur from cloud-to-cloud, cloud-to-ground, cloud-to-air, or within a cloud. And lightning can take many different forms, from streak lightning that appears as a single arc to ball lightning, which manifests as a glowing ball that floats in the air, may move slow or fast or remain in one place, and often explodes with a loud bang.