Lightning safety outdoors: U.S. and Japanese guidance compared
The National Weather Service (NWS) says lightning strikes the United States about 25 million times a year and kills about 20 people in the U.S. each year, with hundreds more severely injured. Its message is short: When Thunder Roars, Go Indoors. If you can hear thunder, lightning is close enough to strike you, and there is no safe place outside when thunderstorms are in the area.
What is safe shelter
NWS defines it as a substantial building with electricity or plumbing, or an enclosed, metal-topped vehicle with the windows up. A tent, picnic shelter, or open-sided pavilion is not on that list. Stay in safe shelter at least 30 minutes after you hear the last sound of thunder.
Inside isn't automatically safe
NWS says a house is a safe place during a thunderstorm as long as you avoid anything that conducts electricity:
- Stay off corded phones, computers and other electrical equipment that put you in direct contact with electricity.
- Avoid plumbing, including sinks, baths and faucets.
- Stay away from windows and doors, and stay off porches.
- Don't lie on concrete floors or lean against concrete walls.
If you're caught outside
NWS stresses that nothing outside is safe, but these last-resort steps may reduce risk:
- Get off elevated areas such as hills, mountain ridges and peaks.
- Never lie flat on the ground; never shelter under an isolated tree or a cliff or rocky overhang.
- Get out of and away from ponds, lakes and other water.
- Stay away from things that conduct electricity, like barbed-wire fences, power lines and windmills.
Myths that get people hurt (NWS)
| Myth | Fact |
|---|---|
| Crouching makes you safe | Crouching doesn't make you any safer outdoors. Get to a substantial building or hard-topped vehicle |
| A tree keeps you dry and safe | Being underneath a tree is the second leading cause of lightning casualties |
| No rain overhead means no danger | "Bolts from the blue" can strike 10 to 15 miles from the storm |
| Lightning never strikes the same place twice | It often does; the Empire State Building is hit an average of 23 times a year |
| Metal attracts lightning | Height, pointy shape and isolation decide where it strikes; metal makes no difference. Don't waste time removing it |
| A victim is still electrified | The body doesn't store electricity. It's safe to touch a lightning victim and give first aid, including CPR |
| You can finish the game first | Many casualties happen because people don't seek shelter soon enough |
How Japan's guidance compares
| Topic | NWS (U.S.) | Japan Meteorological Agency |
|---|---|---|
| Safe places | Substantial building; enclosed, metal-topped vehicle | Reinforced-concrete buildings, cars (not convertibles), buses, trains; wooden houses are basically safe too, and safer still if you keep 1 m from electrical appliances, ceilings and walls |
| Dangerous places | Elevated areas, water, open areas | Sports fields, golf courses, outdoor pools, levees, beaches, the sea; mountain peaks and ridges |
| Trees | Never shelter under an isolated tree | Stay at least 2 m from every part of a tall tree (trunk, branches, leaves). Most deaths sheltering under trees come from "side flash", lightning jumping from the tree to a person |
| No shelter nearby | Last-resort tips above | A "protected zone": at least 4 m from a tall object such as a utility pole, within the area where you look up at its top at 45 degrees or more; keep low and don't hold things above your body |
| When to move again | At least 30 minutes after the last thunder | Move to safe shelter after lightning activity has stopped for 20 minutes or more |
JMA's page credits its guidance to the Society of Atmospheric Electricity of Japan's safety Q&A. The two agencies agree on the essentials. Where they differ, we'd follow the more cautious figure: wait 30 minutes.
Planning a trip around storms (our suggestions)
- Check the forecast for thunderstorms before you go, and plan to be off peaks and ridges by early afternoon on storm-prone days.
- At camp, know where the nearest building or your car is, and move there at the first thunder.
- If someone is struck, call 911 and start CPR if needed; it is safe to touch them. See Finding a CPR and first aid class.
Everyday
Check the forecast for thunderstorms before a hike or camp, and note where the nearest building or car is.
When it counts
At the first thunder you move to real shelter, instead of waiting under a tree.
Sources and when we checked them
- National Weather Service, Lightning Tips (checked 2026-10-31)
- National Weather Service, Lightning Safety (checked 2026-10-31)
- National Weather Service, Lightning Myths (checked 2026-10-31)
- National Weather Service, Lightning Safety Tips and Resources (checked 2026-10-31)
- Japan Meteorological Agency, protecting yourself from lightning (in Japanese) (checked 2026-10-31)
- Japan Meteorological Agency, lightning disasters (in Japanese) (checked 2026-10-31)
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