How far away is thunder and lightning?

Thunder may be heard up to 10 miles away from the location of the lightning strike. If you hear thunder, it's a sign that you're within striking distance of the storm. When lightning hits, the air temperature along the lightning path can reach 50,000 degrees Fahrenheit (five times hotter than the surface of the sun).

The surrounding air immediately cools and shrinks following the flash, producing the thunderous sound wave. Although lightning strikes only strike one location on the earth, they can travel several miles through the air. A crisp click or crack is usually an indicator that a lightning channel has passed nearby. Lightning is at least several miles distant if you hear a rumbling.

During wet summer weather, the "flash-to-bang" strategy can keep you safe from lightning strikes. The National Weather Service suggests taking cover for at least 30 minutes if the period between the lightning flash and the sound of thunder is shorter than 30 seconds. This indicates that lightning is less than 6 miles away and that the next strike may harm you.