Ultimate guide to lightning safety

Lightning is one of nature’s most beautiful yet unpredictable and deadly phenomena. No place outside is safe during a thunderstorm. Understanding the science and following official safety guidelines drastically reduces your risk of being struck!

The Numbers

• ● Frequency: The United States experiences roughly 25 million cloud-to-ground lightning strikes every year.
• ● Extreme Heat: A bolt of lightning can reach 50,000°F—five times hotter than the sun's surface.
• ● The 10-Mile Rule: Lightning can strike 10 miles away from rain. If you hear thunder, you are in danger!
• ● The Distance Formula: Count the seconds between the lightning flash and the thunder, then divide by 5 to calculate its distance in miles.
• ● Long-Term Impact: Not everyone who gets struck by lightning will die. In fact, about 90% of victims survive, but many survivors face lifelong neurological issues and chronic pain. In an average year, 20 people are killed by lightning, and another 500 are injured.

NWS Slogans:  

• ● “When Thunder Roars, Go Indoors!”
• ● “See a Flash, Dash Inside!”

Finding Safe Shelter

• ● Safe: Fully enclosed buildings (wiring and plumbing allows an avenue for the electric charge to reach the ground and be “grounded”) or hard-topped, metal vehicles (the metal shell protects you, not the rubber tires).
• ● Unsafe: Picnic pavilions, tents, carports, porches, and sheds. You need to be in an enclosed space to be fully protected. 
• ● If Stranded Outside: Get into a safe shelter! If time does not allow, move down from elevated areas. Avoid isolated trees, towers, and utility poles (lightning typically strikes the tallest object). Immediately exit bodies of water, and avoid metal conductors. If in a group, spread out. 

Indoor Safety

• ● Avoid Plumbing: Do not shower or wash dishes; water and pipes conduct electricity.
• ● Disconnect Electronics: Avoid corded phones and plugged-in appliances. (Unplugged cell phones/laptops are safe).
• ● Avoid Concrete: Do not lean on concrete walls or lie on concrete floors (they contain conductive metal rebar).
• ● Stay Away from Windows: Lightning can shatter glass.

The 30-Minute Rule & First Aid

• ● The 30-Minute Rule: Wait 30 minutes after the last rumble of thunder before going back outside. Most people get struck by lightning AFTER the storm has passed because they go back outside too soon. This 30 minute buffer ensures the dangerous trailing edge of the thunderstorm has completely passed.
• ● First Aid: Victims do not hold an electrical charge and are safe to touch. Call 911, immediately administer CPR/AED if they are not breathing, and safely move them indoors.