Lightning Safety 101
Lightning strikes the ground approximately 25 million times each year in the United States alone! According to the National Weather Service, the chance of an individual in the U.S. being killed or injured during a given year is one in 240,000.
Assuming an average life span of 80 years, a person's odds over their lifetime becomes one in 3000. Assuming the average person has ten family members and others with whom they are close, then the chances are one in 300 that a lightning strike will closely affect a person during their lifetime.
When Thunder Roars, Go Indoors
Avoiding lightning injury is quite simple, really. If you hear thunder, seek shelter. This is based on the fact that the distances that sound travels are well within the range of a lightning strike. Furthermore, you may miss lightning because the clouds or other terrain hides it: there is simply no safe place outdoors.
Seek shelter in a substantial building or an all-metal vehicle. Small shelters such as golf, bus, and rain shelters may increase a person’s risk of being struck due to side splash as the lightning flows over the building (a so-called: “Faraday-Suit”). All metal vehicles are safe because the metal will diffuse the current around the occupants to the ground. It is a myth that rubber tires provide insulation.
If you are caught in a storm outside without a safe building or vehicle:
Stay away from metal objects and those items that are taller than you. Avoid areas near power lines, pipelines, ski lifts, and other large steel objects. Do not stand near or under tall, isolated trees, hilltops, or at a lookout or other exposed area. In a forest, seek a low area undergrowth of saplings or small trees. Seek a clearing free of trees makes a person the tallest object in the clearing.
If you are entirely in the open: stay far away from single trees to avoid lightning splashes and ground current. A good position is to squat down with your knees fully bent and your feet together or to sit cross-legged or to kneel on the ground. Keeping the feet together prevents you from being injured by the ground current.
If you are in a group of people:
Spread out far apart enough that a single lightning strike will not take out the entire group. The Wilderness Medical Society's guidelines state "20-30 feet apart", however other organizations such as the Boy Scouts have their own policy ("at least 100 fee apart").
The group members should be separated at least 20 feet (6m) to limit the potential for mass casualties due to a strike and the ground current. This allows the individuals to watch others and to rescue them if struck. If you are on the water, seek the shore and avoid being the tallest object near a large body of water. Being within visual distance of each other is recommended, and keep track of accountability by loudly counting off to ensure each member of your party is still safe.
Avoid open doors and windows, fireplaces and metal objects such as sinks and plugged-in electrical appliances. Do not talk on the telephone as telephone lines may not be grounded like electrical wires.
The Worst Places To Be In A Thunderstorm