Lightning Safety Week: June 23-29, 2013 (updated 6/28)

Lightning Safety: When Thunder Roars, Go Indoors!
Lightning Safety Week: June 23-29, 2013

What's New?

Summer is the peak season for one of the nation's deadliest weather phenomena--lightning. Though lightning strikes peak in summer, people are struck year round. In the United States, an average of 54 people are killed each year by lightning, and hundreds more are severely injured.

when thunder roars go indoors sign

Safety: Learn what you need to do to stay safe when thunderstorms threaten.

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Victims: Learn what happens to people who are struck by lightning and look at fatality statistics for the U.S.

animation of Charged Cloud

Science: Learn how thunderstorms develop and what happens during a lightning discharge.


Myths and Facts: Get answers to many of the questions you have always wondered about


Teachers: find curriculum guides, presentations games, activities, and more. Kids: Download games, videos, coloring pages and other fun stuff. publications and other resources More Resources: Download toolkits, posters, pamphlets, and other information to help communities, organizations, and families stay safe from the dangers of lightning
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 A Message from Wisconsin Emergency Management

(MADISON) – Every year, lightning kills more than 50 Americans and injures hundreds of others leaving them with lifelong pain and in some cases permanent neurological disabilities. Here in Wisconsin, 25 people have been killed and 208 injured as a result of lightning since 1982. You can protect yourself and your family by knowing these simple lightning safety facts and tips:

  • If you hear thunder, you are in danger. Don’t be fooled by blue skies. If you hear thunder, lightning is close enough to pose an immediate threat. Don’t wait, seek shelter immediately. Remember: When Thunder Roars…Go Indoors!
  • A fully enclosed building with wiring and plumbing offers the best protection. Sheds, picnic shelters and covered porches DO NOT protect you from lightning.
  • If a building is not available get into a hard-topped metal vehicle and close all the windows.
  • Stay inside a safe building or vehicle for at least 30 minutes after you hear the last clap of thunder.
  • Don’t use a corded phone except in an emergency. Cordless and cell phones are safe to use.
  • Keep away from electrical equipment and wiring.
  • Because water pipes conduct electricity, don’t take a bath or shower or use other plumbing during a storm.
  • Stay away from isolated tall trees, towers or utility poles. Lightning tends to strike taller object in an area.
  • Get an Emergency Weather Radio. It will broadcast the latest forecast for thunderstorms. Remember, any thunderstorm, whether it is severe or not, can produce deadly lightning.

Act fast if someone is struck by lightning

  • Lightning victims don’t carry an electric charge and are safe to touch and need urgent medical attention. Cardiac arrest is the immediate cause of death. Call 911 immediately.
  • Give CPR if the person is unresponsive or not breathing. Use an Automatic External Defibrillator if one is available.
  • If possible, move the victim to a safer place. Lightning can strike twice. Don’t be a victim. 

 Lightning Facts

  • Lightning occurs in all thunderstorms; each year lightning strikes the United States 25 million times.
  • Lightning often strikes the same place repeatedly, especially tall isolated objects.
  • Most lightning victims are in open areas or near a tree.
  • The energy from one lightning flash could light a 100-watt light bulb for more than 3 months.
  • The air near a lightning strike is heated to 50,000°F—five times hotter than the surface of the sun!
  • The rapid heating and cooling of the air near the lightning channel causes a shock wave which results in thunder.   

Lightning Myths and Facts

Myth: Rubber tires on a car protect you from lightning by insulating you from the ground.

Fact: The metal roof and sides protect you, NOT the rubber tires. When lightning strikes a vehicle it goes through the metal frame into the ground.  Don’t lean on the vehicle doors during a thunderstorm.

Myth: If trapped outside and lightning is about to strike you should lie flat on the ground.

Fact: Lying flat increases your chance of being hit by a ground current. If you are caught outside in a thunderstorm keep moving toward a safe shelter.

Myth: If thunderstorms threaten while you are outside playing a game it is OK to finish before seeking shelter.

Fact: Many lighting casualties occur because people do not seek shelter soon enough. No game is worth death or lifelong injuries. Seek shelter immediately if you hear thunder. Adults are responsible for the safety of children.

Additional Information

For additional information about lightning safety and awareness go to You can also contact your local public health department, county emergency management director or your local National Weather Service office. 

NOAA Press Release - Fishing Tops U.S. Lightning Death Activities


Wisconsin Severe Weather Climatology 

Science of Lightning 
At any given moment there are eighteen hundred thunderstorms in progress somewhere on Earth and sixteen million thunderstorms each year. Scientists studying lightning have a better understanding today of the process that produces lightning and there is still more to learn.

The presence of ice and liquid water in the same region of a cloud is critical in the development of lightning. Clouds that do not have large quantities of ice and water co-located fail to produce lightning. In a thunderstorm…the ice particles vary in size from small crystals to larger hailstones. Due to the rising and sinking motions within storms…there are numerous collisions between ice and water particles of different sizes. The smaller particles tend to take on a positive charge and are lifted high into the cloud...while the heavier…negatively charged particles fall toward the Earth.

Through this process the upper portions of the cloud become positively charged and the lower portions of the cloud become negatively charged…increasing the electrical potential within the cloud. As the negatively charged particles fall toward the Earth...the Earth responds by generating a slight positive charge near the surface. Over time...the electric potential increases to the point where it can overcome the insulating effect of the air and creates a static spark: Lightning.

This spark can extend from the cloud to the the case of cloud-to-ground lightning...or between the two charged regions within the cloud...called in-cloud lightning.

One of the charged areas in the cloud will send out a “feeler” toward an area with the opposite charge. That other area will send a “feeler” back. This process continues back and small steps...until the two feelers meet and the electricity transfer begins. The “feeler” process occurs over a few fractions of a second and is invisible to the human eye. The electricity transfer occurs over several short bursts through the channel or as a longer…sustained burst. The entire process is over within a few seconds.

The channel through which the lightning travels is roughly the width of the pencil. The air within this space heats very rapidly to around fifty thousand degrees Fahrenheit…five times hotter than the surface of the sun. As the air heats it expands. After the transfer of electricity is finished the air cools just as quickly and collapses. The rapid expansion and collapse of the air is what we hear as thunder.

A bolt of lightning can reach up to ten miles from the parent thunderstorm. This is why we say if you are close enough to hear thunder…you are close enough to be struck by lightning.
...courtesy of Kevin Huyck of WFO Duluth

Kapela, WFO Milwaukee

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