Lightning strike

A lightning strike or lightning bolt is a special kind of event where a big spark of electricity jumps between the sky and the ground. This happens because of something called lightning, which is a powerful electric discharge. Most of these strikes start in tall, heavy clouds known as cumulonimbus clouds and end up hitting the ground. This type is called cloud-to-ground lightning.

There is also a less common kind of lightning that goes the other way, from the ground up into the clouds. This happens when something tall, like a tower or a tree, sends a spark up to the clouds. This is called ground-to-cloud lightning.

Lightning happens a lot in nature. About a quarter of all lightning events around the world are strikes that reach from the sky to objects on the earth. Many other lightning flashes happen high in the sky between clouds. Even airplanes can get struck by lightning once or more each year, but because of how they are built, this is usually not a big problem for them. In fact, flying through clouds can sometimes even create lightning strikes.

Epidemiology

See also: Lightning injury

Lightning strikes can hurt humans in several ways. One way is a direct strike, where the lightning passes through the body, causing serious damage inside. Another way is when something a person is touching gets electrified by the lightning. Lightning can also jump to a person from nearby objects, or cause injuries from the shock wave.

Lightning can also affect people indirectly. When lightning strikes, the ground can become electrically charged, and this charge can travel through a person's body, causing injury. The lightning can also create strong pulses that might affect medical devices like pacemakers.

There are many lightning strikes every day, and while most people survive, some can be seriously hurt or even lose their lives. It’s important to stay safe during thunderstorms by finding enclosed spaces and avoiding open areas or tall objects.

Effect on animals

Lightning strikes can be dangerous for animals, especially farm animals like cattle, sheep, and horses. These animals are often hurt when lightning creates a difference in electricity between two points on the ground. Because their legs are far apart, the electricity can flow through their bodies, which can harm them badly.

Farmers can help protect their animals by using special grounding rods along fences and by keeping animals away from trees during storms. Trees can attract lightning and put animals near them at risk.

Effect on nature

Impact on vegetation

In places with few people, like the Russian Far East and Siberia, lightning strikes are a big reason why forests catch fire. The smoke and fog from a huge forest fire can even create more lightning strikes, starting new fires far away.

Shattering of rocks

Main article: Electromechanical disintegration

When lightning hits water inside cracks in rocks, the water heats up very fast and turns to steam. This can break the rocks apart and move big boulders. This process might help wear down mountains in warm areas that have never had ice ages. Signs of lightning strikes can be found in unusual magnetic fields.

Electrical and structural damage

Telephones, modems, computers, and other electronic devices can be harmed by lightning. This happens because strong electric surges can travel through phone lines, internet cables, or power outlets.

Lightning creates very fast-rising electric currents. Even though lightning is a type of steady electric flow, it behaves similarly to alternating currents in wires, causing the electric flow to mainly travel along the outer parts of conductors.

Prevention and mitigations

Protection systems

Main articles: Lightning rod, Lightning arrester, and Surge protector

Many tools, such as lightning rods, help protect buildings from lightning. A lightning rod is a metal rod connected to the ground. It gives lightning a safe path to the earth if it hits the building.

Monitoring and warning systems

We cannot predict exactly when and where lightning will strike. But we have tools that can tell us when the chance of lightning is high. These tools watch for lightning from the ground and from satellites.

Personal safety

See also: Lightning injury § Prevention

It is important to have a plan for safety when thunderstorms happen. Start your plan as soon as you see lightning or hear thunder. Lightning can strike even if it looks like there is no storm nearby.

One way to guess how far lightning is from you is to count the seconds between the flash and the thunder. Then divide that number by three to get the distance in kilometers, or by five for miles. If the time is 25 seconds or less, the lightning is very close, and you should take cover right away.

The safest place to be is inside a building or a car. Avoid tall objects and metal things. If you are inside, stay away from electrical things and pipes, such as taking a shower. It is still unsafe for up to 30 minutes after the last lightning or thunder.

If you are outside and cannot get inside, try to find the lowest ground, like a valley. Do not stand near water, as lightning can travel through it. If your hair stands up, lightning may be about to strike — get inside as fast as you can. If you cannot, kneel and lean forward, but do not lie flat on the ground.

Notable incidents

Earth-bound

In 1769, lightning struck a church in Brescia, Italy, causing a big explosion that hurt many people. In 1902, lightning damaged the top of the Eiffel Tower in France. In 2005, lightning struck a tree where some cows were standing, and many cows were hurt because the electricity passed through them. In 2016, a big lightning strike hurt many people at a music festival in Germany. In 2026, lightning struck a group of people at a rally in Brazil, hurting several of them.

In-flight

Airplanes often get hit by lightning, but usually, they are built to handle it. In 1963, a plane crashed during a storm and everyone on board was hurt. In 1971, a plane’s fuel tank caught fire after being struck by lightning, but one person survived by falling from the plane and landing safely in the rainforest. In 2019, a plane was struck by lightning right after taking off, which caused problems and led to a fire on the ground.

Most-stricken human

Roy Sullivan, a park ranger, survived being struck by lightning seven times before he passed away in 1983.

Longest lightning bolt

In 2017, a lightning bolt was detected that stretched 515 miles from Dallas, Texas, to Kansas City, Missouri. This was the longest lightning bolt ever recorded.