Lightning Safety Explained

Lightning kills more people in a typical year than tornadoes do, mostly because it's treated as a minor inconvenience rather than the hazard it actually is. Unlike a tornado or hurricane, there's no watch-then-warning buildup — a storm can produce a lethal strike from the very first flash, often before rain even starts falling where you are.

The 30-30 rule

The standard guidance for deciding when to take lightning seriously is simple: if the time between seeing a flash and hearing its thunder is 30 seconds or less, the storm is close enough to be dangerous — get to substantial shelter immediately. After moving to shelter, wait at least 30 minutes after the last thunderclap before going back outside, since a storm's trailing edge can still produce strikes well after the heaviest rain has passed. Sound travels roughly one mile every 5 seconds, so a 30-second gap corresponds to about 6 miles — already within the distance lightning can travel from a parent storm cell.

There's no safe place outdoors

Open fields, under an isolated tree, a golf course, a ball field, a boat on open water — none of these are safe, and some are actively more dangerous than open ground because they make you (or whatever you're standing near) the tallest object around. If you're caught outside with absolutely no way to reach a substantial building or hard-topped vehicle, the guidance is damage control, not safety: get off high ground, avoid being the tallest object or standing near one, spread out from other people, and minimize contact with the ground by crouching on the balls of your feet rather than lying flat. None of this makes you safe — it only reduces risk while you get to real shelter as fast as possible.

A "substantial" shelter means a fully enclosed building with wiring and plumbing, or a hard-topped vehicle with the windows up — the metal frame of a car helps conduct a strike around the occupants to the ground, not the rubber tires, which is a common misconception (see below).

Indoor hazards people don't expect

Being inside is dramatically safer, but not risk-free, because lightning can travel through a building's wiring and plumbing. During a storm:

Avoid corded phones. A landline handset wired into the building can conduct a strike. Cordless phones and cell phones not plugged into a charger are fine.
Avoid plumbing — showers, baths, washing dishes — since metal pipes and the water itself can conduct electricity from a strike on the building.
Stay away from windows and doors, and avoid leaning on exterior walls.
Unplug sensitive electronics if you want to protect them from a power surge, though this is a property concern, not a personal safety one.

Common myths

Myth: Rubber tires or rubber-soled shoes protect you from lightning.
Reality: A car's protection comes from its metal frame routing the current around the occupants to the ground, not its tires. Rubber-soled shoes provide no meaningful protection against a strike.

Myth: Lightning never strikes the same place twice.
Reality: Tall, prominent structures (skyscrapers, towers, lone trees) can be struck repeatedly — height and isolation attract strikes regardless of history.

Myth: If it isn't raining, it's safe.
Reality: Lightning can strike as far as 10 miles from the parent thunderstorm, well outside the rain shaft itself — sometimes described as a "bolt from the blue" striking under clear-looking sky.

If someone is struck

A person struck by lightning does not retain an electrical charge and is completely safe to touch immediately — this is one of the most important things to know, since hesitation to help costs time that matters. Call 911 right away. If the person isn't breathing or has no pulse, begin CPR if you're able; an automated external defibrillator (AED), if one is available, can also be used. Lightning strike injuries often include cardiac arrest, burns, and ruptured eardrums, so get professional medical evaluation even if the person seems alert and recovered.

RadarBug's lightning layer, sourced from the Blitzortung detection network, shows recent strikes with an optional proximity alert radius — useful for situational awareness, but it's a notification, not a substitute for following the 30-30 rule yourself. See the official safety resources linked from the Lightning Alerts section of the Documentation page for more from NOAA's National Weather Service, the CDC, and the National Lightning Safety Council.