Taking a shower during a lightning storm is not recommended. A lightning strike can be conducted from many miles away through a water pipe.
A bolt of lightning can travel through plumbing, into metal pipes, and shock anyone who comes into contact with a faucet or appliance. Metal pipes are not only excellent conductors of electricity, but they also carry tap water laden with impurities that help conduct electrical current.
In the real world, the odds of being harmed this way are extremely minute. But it is not unheard of. Ron Holle, a former meteorologist with the National Oceanic and Atmospheric Administration who tracks lightning injuries, estimates that 10 to 20 people in the United States are shocked annually while bathing, using faucets or handling appliances during storms. “There are a ton of myths about lightning,” he said, “but this is not one of them.”
In a storm, a protected building acts somewhat like a metal cage. Electricity from a lightning strike is conducted around you and eventually dissipates into the ground. There is no real risk unless you touch something connected to plumbing, electrical wiring, another conducting path.
Dr. Mary Ann Cooper, who runs the Lightning Injury Research Program at the University of Illinois at Chicago, said people had been shocked and even killed washing dishes, doing laundry, sitting in bathtubs in storms.