Lightning: You Do Not Have to Be Struck to Be Hurt

Call 911 for anybody struck by lightning, and follow the dispatcher’s instructions — they will tell you exactly what to do, including whether and how to start CPR. Do not move a person who may have fallen unless you have to.

The National Weather Service names five ways lightning injures people, and the one that causes the most deaths and injuries is not being struck.

It is ground current — and the Weather Service describes it plainly: “When lightning strikes a tree or other object, much of the energy travels outward from the strike in and along the ground surface.” You were not hit. The tree was. The energy came to you through the ground you were standing on.

That single fact rewrites the whole risk, because almost everybody pictures lightning as a bolt that finds one unlucky person. It is closer to something that arrives across a radius.

The five ways, in the Weather Service’s own words

Ground current — “much of the energy travels outward from the strike in and along the ground surface.” This one causes the most lightning deaths and injuries.

Side flash — “occurs when lightning strikes a taller object near the victim and a portion of the current jumps from taller object to the victim.” The classic version is sheltering under a tree.

Conduction — “Lightning can travel long distances in wires or other metal surfaces.” Which is why indoor safety is about plumbing and cords rather than about being under a roof.

Direct strike — “A person struck directly by lightning becomes a part of the main lightning discharge channel.” NWS notes it is “not as common as the other ways people are struck.”

Streamers — which “develop as the downward-moving leader approaches the ground.”

Four of those five reach a person who was not hit by the bolt. Standing near the strike is the risk, and distance from the tall object is the protection.

The rule, and it is shorter than people think

“If you hear thunder, lightning is close enough to strike you.”

There is no distance calculation, no counting seconds between flash and bang, no judgement to make. Thunder audible means go inside. The Weather Service’s instruction is to “immediately move to safe shelter”, and the slogan — created by and for the Deaf and Hard of Hearing community — is “Flash, Dash Inside.”

And the part people get wrong at the other end:

“Stay in safe shelter at least 30 minutes after you hear the last sound of thunder.”

Thirty minutes after the last thunder, not after the last rain. A storm moving away is still throwing lightning, the sky looks finished long before it is, and going back out to the yard or the course or the trail during that half hour is how a calm-looking evening produces a casualty.

What counts as shelter, and what does not

Safe, per NWS: “a substantial building with electricity or plumbing or an enclosed, metal-topped vehicle with windows up.”

Note what makes a building safe — the wiring and the pipes, which give current a path that is not you. A structure without them is not shelter in this sense.

Not safe, and each of these is named explicitly: sheltering “under an isolated tree”, using “a cliff or rocky overhang for shelter”, and staying on “elevated areas such as hills, mountain ridges or peaks.”

A ramada, a dugout, a bus stop, a golf shelter, a covered patio open at the sides — none of these is a substantial building with electricity or plumbing. They keep rain off. That is a different job.

If you are caught out with nowhere to go

NWS’s instructions, and the second one surprises people:

Get off high ground immediately — “Immediately get off elevated areas.”

Do not lie flat. Lying down puts more of you in contact with the ground, and ground current is the mechanism that hurts the most people.

Get away from water — “get out and away from ponds, lakes and other bodies of water.”

Get away from anything that conducts — “stay away from objects that conduct electricity (barbed wire fences, power lines, windmills, etc.).” Fence lines run for miles and carry current a long way from the strike.

Indoors is not automatically safe either

Because of conduction, NWS gives indoor instructions too:

“Stay off corded phones, computers and other electrical equipment.” A cordless or mobile phone is fine; the cord is the problem.

“Avoid plumbing, including sinks, baths and faucets.” So the shower and the washing up both wait.

“Stay away from windows and doors.”

How common is this, honestly

NWS says lightning strikes the United States about 25 million times a year and kills about 20 people. Both numbers are worth holding at once: it is an enormously common event and a rare cause of death.

Which is the right reason to follow the rules rather than to be frightened of them. The behaviour that keeps the death toll at around twenty is people going inside. It is not luck.

After a strike

Call 911 immediately, and follow the dispatcher’s instructions. They will tell you what to do for the person in front of you, including how to start CPR if it is needed. That is a better source of instruction in the moment than any web page, and it is the reason this page does not try to teach resuscitation.

Come to an emergency room for anybody who was struck, near a strike, knocked down, or who has burns, confusion, hearing change, numbness, weakness, or a heart rhythm that feels wrong — even if they got up and walked away. A lightning injury is an electrical injury, and electrical injuries are the category where how somebody looks afterwards is least informative.

Our emergency rooms are open every hour of every day and are walk-in, with CT, X-ray and a full laboratory in the building. Go to the nearest one, and if another emergency department is closer, that one is the right answer tonight.

If you are unsure, come in — this list is not exhaustive and you are not expected to assess an electrical injury yourself.

Questions people actually ask

The storm is clearly moving away and the rain has stopped. Can I go back out? Thirty minutes after the last thunder is the Weather Service’s rule, and rain stopping is not the same event.

Is my car safe? An enclosed, metal-topped vehicle with the windows up is on NWS’s safe list. A convertible, a golf cart, an open-cab utility vehicle and a motorcycle are not.

I was near a strike but definitely not hit, and I feel strange. That is exactly the situation this page exists for — four of the five mechanisms do not require being hit. Get seen.

Does a lightning victim carry a charge that could hurt me? Call 911 and let the dispatcher direct you. They will tell you whether and how to begin help, and this page is not going to publish a claim about it that we cannot cite.

Should I count the seconds between the flash and the thunder? No. The rule is that hearing thunder at all means lightning can reach you.

My power went out and I have a hot house now. Then two things are true at once, and the heat one has its own page.

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Thunder means go in. Thirty minutes after the last thunder means you can come back out. Call 911 for anybody struck, and come in for anybody who was near a strike even if they seem fine. Both of our emergency rooms are open 24 hours a day, every day of the year — walk in, no appointment and no referral. Find your nearest emergency room →

Related reading: flash floods and desert washes · which door do you need

Sources

31. Lightning Safety — National Weather Service, National Oceanic and Atmospheric Administration. https://www.weather.gov/safety/lightning
33. Lightning Safety Tips — National Weather Service. https://www.weather.gov/safety/lightning-tips
34. How People Are Struck by Lightning — National Weather Service. https://www.weather.gov/safety/lightning-struck

This article is general information, not a diagnosis. It does not teach resuscitation — call 911 and follow the dispatcher. If you are unsure, come in — this list is not exhaustive and you are not expected to assess an electrical injury yourself. If it might be an emergency, treat it as one and call 911.