FLAGSTAFF - The deaths of two people at a scenic overlook in Northern Arizona last week bring to 14 the number of people killed by lightning strikes in the U.S. this year, according to the National Weather Service.
Many of the victims were enjoying summertime activities like sightseeing, boating, camping and fishing.
Weather experts say that when thunderstorms roar, you should get out of the water, drop the sporting equipment and flee to a safe area inside a building or a vehicle.
Lightning flashes 30 million times each year in the continental United States, mostly from cloud to cloud, said Richard Orville, professor at Texas A&M University's Department of Atmospheric Sciences.
About 10 percent of lightning hits the ground, where it can travel through trees, soil, plumbing and electric wiring.
Those cloud-to-cloud strikes start about 15 minutes before the ground strikes and thunder will roar, giving people a heads-up on when to seek shelter, Orville said.
"It's not a hard rule; there are exceptions to it. But in terms of a guideline, it works."
The National Weather Service advises people to stay indoors 30 minutes after that first flash of lightning or clap of thunder.
Arizona and Florida are leading the nation so far this year in lightning fatalities, with three each.
Places like Florida and Texas that have the right combination of moisture and heat have lightning strikes year-round, but in Arizona they are most common during the monsoon season.
The couple killed Tuesday near Jacob Lake were sitting beneath a rock wall at a scenic overlook that got hit by lightning, authorities said.
Others killed this year have been under trees in Missouri and New York, fishing on a boat in Louisiana, walking on the beach in Florida, camping in California and at a park in Illinois.
Your odds of being struck by lightning depend on where you live, the climate, how much time you spend outdoors and the time of year.
People in the central Florida peninsula, where the lightning concentration is the highest in the United States, according to the National Weather Service, are more likely to be hit by lightning than people in the Pacific Northwest where thunderstorms are rare.
"People in this region who spend much of their lives indoors might win the lottery before they were struck by lightning," the weather service said.
Knowing where lightning will strike is mostly unpredictable, weather experts say. While it tends to favor tall, isolated objects, it "has a mind of its own," said Chris Outler, a meteorologist with the National Weather Service in Flagstaff. "It will really do what it wants."
Most lightning deaths occur between June and August when people are outdoors enjoying the warmer weather, according to the National Weather Service.
Nearly two-thirds of the 238 people killed by lightning in the past seven years were enjoying recreational activities - a number that varied from 26 in 2011 to 48 in 2006, according to a study by lightning-safety specialist John Jensenius Jr.
The study dispels the myth that golfers are highest on the fatality list. Fishing led the list of 12 activities that accounted for more than half of the deaths from 2006 to 2012, followed by camping and boating. Golfing came in at No. 9.
When inside, weather experts say you should unplug appliances, avoid talking on a phone that's connected to the wall and not take a shower or bath when thunderstorms are brewing.
Orville, the Texas A&M professor, said his own home sustained $5,000 in damage a few years back when lightning hit a tree in his backyard, moving through electrical circuits and destroying the garage- door opener, the washer and dryer and lighting in the swimming pool.