Lightning
- View
No safe place outside, why your car protects you and what does not, and the half of lightning deaths that happen after the rain stops.
In this lesson you will
- State the current NWS lightning message and the status of the 30-30 rule.
- Explain how a vehicle protects its occupants, and identify vehicles that do not.
- List the five lightning injury mechanisms.
- Apply the 30-minute rule and the correct first aid.
The current message
The NWS states its position in three sentences, and they are worth having exactly:
There is no safe place outside when thunderstorms are in the area.
If you hear thunder, you are likely within striking distance of the
storm. Just remember, When Thunder Roars, Go Indoors.NWS lightning safety, read 11 September 2026. Quoted in full.
Many spotters were taught to count the seconds between flash and thunder and take shelter under thirty. The NWS lightning safety pages do not carry that rule. The lead guidance is the sentence above, and its logic is simpler and stricter: if you can hear thunder at all you are in range, so the count is not a decision you need to make. You will still see 30-30 on legacy pages and in older handouts. It is not the current message.
Lightning strikes the United States about 25 million times a year and kills about 20 people annually, with hundreds more severely injured. Published averages differ depending on the years they cover and they have been falling for decades, so quote the figure with its source rather than from memory.
Lightning kills across the whole country and in every kind of terrain: beaches, summits, back gardens, car parks, fields, and up trees. Flash density is higher in the Southeast and Florida in particular, which raises the odds there, but there is nowhere in the United States where this lesson does not apply.
Bolt from the blue
Lightning can strike more than ten miles from the rain that produced it, under clear sky. Which produces the statistic that should change your behavior more than any other in this lesson: more than half of lightning deaths happen after the storm has passed.
The reason is behavioral rather than meteorological. People wait out the rain, the rain stops, they come out, and the storm is still close enough. Wait 30 minutes after the last thunder before going back outside, and restart the thirty minutes if you hear thunder again.
Vehicles
A hard-topped metal vehicle with the windows up is genuinely good protection, and almost everybody believes it for the wrong reason. The NWS is explicit about the mechanism:
"the outer metal shell of hard-topped metal vehicles does provide protection to those inside a vehicle with the windows closed." The current runs over the shell and then, in the NWS's own description of a strike, through the tires to the ground. The tires are part of the path, not an insulator.
| Protects you | Does not |
|---|---|
| Hard-topped car, windows up | Convertible or soft-top |
| Van or hard-top truck cab | Fiberglass-bodied vehicle |
| Enclosed metal cab on machinery | Motorcycle, ATV, bicycle |
| Open-cab tractor, golf cart, mower |
The rule is a continuous metal shell around you. Anything you can be rained on in, or that is made of fiberglass or canvas, is not on the left column no matter how large it is.
Windows up. Hands off anything that connects to the outside: the radio, a CB, the ignition, door handles, any metal path from inside to outside. The shell works by carrying the current around you, and you do not want to be part of the circuit. The vehicle frequently does not survive even when the occupants do: melted antenna, destroyed electronics, shattered rear window, blown tires.
Five ways it reaches you
- Direct strike
- The flash hits you. Rarest, and the most often imagined.
- Side flash
- The flash hits something taller nearby, usually a tree, and jumps sideways to you. This is why sheltering under a tree is not shelter.
- Ground current
- The current spreads out through the ground from the strike point and passes up one leg and down the other. This kills the most people, and it is why there is no safe distance from a strike point in the open.
- Conduction
- Along wiring, plumbing, fences and metal structures, which can carry it a very long way indoors. The reason to stay off a corded phone and out of the shower in a storm.
- Upward streamer
- The upward discharge from an object on the ground that does not end up completing the main channel. Still carries enough current to injure or kill.
If somebody is struck
This is the myth that kills people twice. A lightning victim holds no electrical charge and is completely safe to touch. Call 911 and start CPR immediately, and use an AED if there is one. Cardiac arrest is the usual cause of death and it is the one that responds to prompt CPR. Hesitating because you think they are electrified costs the only minutes that matter.
Check your own safety first, because the storm that struck them is still there and may strike again in the same place. Move the casualty if you can do it safely and quickly.
Check yourself
The rain has stopped, the sky overhead is clearing, and you last heard thunder about ten minutes ago. What is the correct action?
- Stay in shelter. The 30 minutes restarts from the last thunder, and clear sky overhead means nothing
- Go out. The storm has passed and the sky above you is clear
- Count the flash-to-bang interval, and go out if it exceeds 30 seconds
- Go out, but stay within ten seconds of shelter
Hint
Two facts in this lesson combine here: how far lightning travels, and when most deaths happen.
Answer
Stay in shelter. The 30 minutes restarts from the last thunder, and clear sky overhead means nothing
Lightning strikes more than ten miles from its parent rain, and more than half of lightning deaths occur after the storm has passed, for exactly the reason described in the second option. Wait the full 30 minutes from the last thunder. The flash-to-bang count in the third option is the 30-30 rule, which the NWS lightning safety pages no longer carry.
Sources
- NWS lightning safety
- NWS, lightning and cars
- NWS, lightning safety tips and resources
- NWS, US lightning fatalities, compiled by the National Lightning Safety Council
- Curran, Holle & López 1997, NOAA Tech. Memo. NWS SR-193: lightning fatalities, injuries and damage reports in the United States, 1959 to 1994