Here’s the thing that surprises most people: lightning loves to hit the same spot repeatedly, especially if it’s tall, pointy, and out in the open. The Empire State Building gets hit nearly 25 times a year on average — and has been struck up to a dozen times in a single storm. That’s not bad luck. That’s just how lightning works. Tall isolated objects are basically magnets for it.
The other big myth is that you’re safe once the storm moves away or the sky above you looks blue. Not true. A specific type of lightning called a ‘bolt from the blue’ can travel sideways out of a storm cloud and strike the ground in a spot that has clear sky directly overhead. According to NOAA, a storm that is 6 miles away can still be dangerous because of these bolts. You might not even hear thunder yet.
The National Weather Service cites research showing that about half of all lightning flashes land roughly 9 kilometers (about 5.5 miles) apart from each other. That research concludes that to be relatively safe, you should be at least 6 to 8 miles away from where a previous flash occurred. That’s way farther than most people assume.
So what do you actually do with this? If you hear thunder at all — even faint, distant thunder — that’s your signal to get inside a sturdy building or a hard-topped vehicle. Don’t wait for the storm to be right on top of you, and don’t head back outside the second the rain stops. The National Weather Service recommends waiting at least 30 minutes after the last clap of thunder before going back outside. The danger window is wider than it looks.
Bottom line: clear skies and ‘the storm passed’ are not green lights to be outside. If you heard thunder in the last 30 minutes, the safest move is to stay inside.