Lightning Storms: 10 Safety Tips You Should Know

Lightning facts and fiction!

August 13, 2020
Lightning Myths
National Weather Service

Lightning can be awesome to watch but, yes, it can be dangerous and even deadly. Did you know: Lightning strikes more than 40 to 50 times a second during June, July and August. So, summer is a good time to learn about nature’s light shows—and 10 basic lightning safety rules. Know your “flash” facts from your fiction. 

What is Lightning?

What you are watching are spectacular electric sparks! Just as you build up static charges when you shuffle your feet along a carpet, so the collision of ice and slush churning in a thundercloud builds up charges.

The slush near the bottom of the cloud builds up a negative charge while the tiny ice crystals carried to the top become positive. Finally, the charges equal out, just like that irritating spark that stings you when you touch something. The giant discharge flows somewhere and about 25% of the time—BANG!—it hits the ground. 

How Far Away is Lightning?

When you see a flash of lightning, start counting the seconds until you hear the following thunder.  Then divide that number by five. The resulting number will tell you how many miles away you are from where lightning just struck.

For example, if that resulting number was 5 seconds, then the lightning struck 1 mile away. If the resulting number was 10 seconds, the lightning was 2 miles away.

How do you calculate the distance of a thunderstorm?

Don’t be fooled by blue skies. Lightning often strikes from 3 to 6 miles away, though it can be as far as 10 miles. According to safety experts, the time to take cover is 6 miles, at minimum.

Follow the 30-30 rule:

If the time between the lightning flash and the crack of thunder is 30 seconds or less, the lightning is about 6 miles away or closer.

  • After you see lightning, start counting to 30. (Use the stop watch or count “One-Mississippi, Two-Mississippi, Three-Mississippi,” etc.)
  • If you hear thunder before you reach 30, seek shelter indoors immediately.
  • Stay inside for at least 30 minutes after hearing the last clap of thunder.

When the storm passes and the skies turn blue again, don’t be fooled. Lightning threats continue much longer period than most people realize. This is why we have 30-minute safety rules.

Predicting Lightning

First, know that every thunderstorm produces lightning. 

Warm, humid summer days are the times when thunderstorms are most likely to develop, especially in the afternoons, as the sun heats the air and heat rises into the atmosphere. Watch as those puffing cumulus clouds start to form. As they build, they’ll start to “tower” vertically upward, and likely to develop into a thunderstorm. 

Flash Fact: If your hair stands up in a storm, it could be a bad sign that positive charges are rising through you. Get yourself indoors immediately.

Summertime is lightning season. Source: NOAA

Can Lightning Kill You?

Surprisingly, lightning is one of the leading weather-related causes of death and injury in the United States. 3,696 deaths were recorded in the U.S. between 1959 and 2003) or cause cardiac arrest.

What Are the Odds of Being Struck by Lightning?

The odds of being killed by lightning is 1 in 700,000. But the odds of being struck in your lifetime is 1 in 3,000.

About 70% of those struck by lightning suffer serious long-term effects such as severe burns, permanent brain damage, memory loss, and personality change.

But some places are more dangerous than others.

  • Kifuka in the African Democratic Republic of the Congo averages 410 lightning strikes per square mile every year.
  • In North America, the champion is the Tampa-Orlando area with 91 flashes per square mile.

Even then, statistics show that not all people face the same risks. Little old ladies are safe, but guys between the ages of 20 and 30 seem to be lightning rods.

If you are a young man in Florida, lightning is not your friend! Source: NOAA

10 Lightning Facts and Fiction

The rules for safety in lightning storms are mostly common sense but you may find a few surprises here. Separate the facts from the fiction.

  1. Do not hide under a tall tree. Being under a tree is just about the worst thing you can do and the second leading cause of lightning casualities. If lightning does hit the tree, there’s the chance that a “ground charge” will spread out from the tree in all directions. Also, don’t touch anything metal outside—such as a fence or bike—as metal can conduct the electricity.
  2. If no shelter is available, crouch low, with as little of your body touching the ground as possible. Lightning causes electric currents along the top of the ground that can be deadly over 100 feet away. Do not lie flat on the ground. While lightning hits the ground, it sends deadly electrical currents in all directions. By lying down, you may even be more likely to be electrocuted because you’re providing more surface area.
  3. Cars are relatively safe shelters and will likely protect you. Make sure the windows are shut. Myth: The car isn’t safe because of rubber tires but because the metal roof and sides divert lightning around you. Convertibles and motorcycles offer no lightning protection.
  4. Stay out of water! Swimming is very dangerous. Wet bodies are a channel for electrical discharge and also water is a good conductor of electricity.
  5. Find shelter quickly. “When The Thunder Roars, Go Indoors” is a common warning. A house or large structure is the safest place you can be during a storm. Note small structures (such as an athletic hut or metal sheds) are only meant to protect from rain and sun and not designed to be lightning-safe with mechanisms for grounding from the roof to ground.

    While being in your home or a large shelter is safest, you may be surprised to discover that one-third of lightning strike injuries still happen indoors! There are a few tips to remember when you are waiting out a storm inside:
     

  6. Stay away from windows and doors in your home, especially metal doors and frames. As tempting as it is, you may not want to stand next to a big window watching a huge lightning storm.
  7. Avoid concrete walls or flooring which often have metal rods or framing for support. Lightning can travel through any metal wires or bars in concrete walls or flooring.
  8. Stay away from plumbing and water indoors during a storm. Metal piping conducts electricity. Never take a bath or shower during a thunderstorm. 
  9. Don’t get near electrical equipment like televisions, stereos, wires, TV cables, and “smart” electronics during a big storm. Don’t use a corded phone (cellular or cordless phones are fine). Talking on the telephone is the leading cause of lightning injuries inside the home! 
  10. Surge protectors do not protect against direct lightning strikes. Unplug equipment such as computers and televisions or anything connected to an electrical outlet. Lightning can travel through electrical systems, radio and television reception systems, and any metal wires or bars. (These items must be installed in conjunction with a lightning protection system to provide whole house protection.)

Flash Fact: Did you know that rubber shoes do nothing to protect you from lightning? 

Credit: NASA

Enjoy the light shows, but stay safe! See more amazing facts about lightning!

About This Blog

The column, “Weather Whispers,” is authored by James Garriss and Evelyn Browning Garriss, historical climatologists and weather addicts!  Whether you enjoy the science of weather or the fascinating folklore or just fun weather phenomena, it’s probably covered by these weather watchers!

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