In Colorado, adventure isn’t just a pastime; it’s a way of life, but with the thrill of the outdoors comes undeniable risk.

Savvy Coloradans tackle these challenges by knowing their skill level and having the right safety equipment. A backcountry skier carries a beacon, probe and shovel. A mountain climber has ropes, a helmet and an emergency radio. A whitewater rafter wears a personal floatation device and has a throw bag and flip lines.

But you don’t need to be a thrill-seeking outdoorsperson scaling a Colorado 14er or navigating a Class IV river to be at risk of lightning.

“Anyone outdoors is at risk of being struck by lightning,” said Chris Vagasky, a meteorologist and lightning data specialist with the National Lightning Safety Council. “Coloradans love their outdoors, whether hiking, climbing a 14er or horseback riding … but the first and most important thing: There is no place outside that is safe during a lightning storm.”

We’re all familiar with those afternoon storm clouds that roll over the mountains and across the Eastern Plains. In Colorado, where residents crave the outdoors, mitigating the danger of being hit by lightning in the spring and summer months may save your life.

Colorado and lightning storms

From 2009 to 2018, Colorado ranked 19th in the nation for the number of cloud-to-ground lightning flashes and 23rd for the density of those flashes, according to the National Weather Service. Yet, Colorado regularly ranks in the top 10 for the number of lightning fatalities, most likely because of how much time residents spend outdoors, Vagasky said.

Colorado was the first state to record a lightning fatality in 2024 after a 51-year-old rancher was killed by lightning in Jackson County around 2 p.m. on May 25 while feeding his cattle. Nearly three dozen cows also died from the strike.

“In Colorado, most lightning-prone areas are in the Eastern Plains,” Vagasky said. “And we say, ‘if you’re going to hike, be done by noon,’ because that’s when the sun heats up the Front Range of the Rockies, and storms develop along the mountains and move into the plains. But anywhere in Colorado is at risk.”

Dr. Arek Wiktor, a surgeon with the UCHealth Burn and Frostbite Center on the Anschutz Medical Campus, said his center sees about two to four patients a year for lightning-caused injuries.

“A common thread with these patients is cardiac or respiratory arrest,” said Wiktor, who is also an associate professor of GI, trauma and endocrine surgery at CU School of Medicine. “As far as injuries, we see varying degrees of burns including deep burns that damage muscles, tendons and bones, and traumatic injuries, such as rib fractures, from being thrown or falling.”

What causes lightning?

Lightning is like that static electricity that builds up on your socks as you shuffle across the carpet and then shocks you when you reach for the door handle. That happens because opposite charges attract, so the negative electrons you’ve created on your body want to rejoin the positive charges and that doorknob is its path.

Lightning is a form of static electricity on a grand scale.

In the clouds, moisture moves up and crystals grow, once large and heavy, they fall. As they fall and smaller crystals continue to rise, they rub together, separating the positive and negative charges – much like your sock dragging across the carpet. Lightning occurs as a result of those charges trying to reunite. That can happen within a cloud or clouds, called in-cloud lightning, or between the clouds and the ground, called cloud-to-ground lightning. Although in-cloud lightning is five to 10 times more frequent, cloud-to-ground lightning is more dangerous, Vagasky said.

“Cloud-to-ground lightning is the really concerning type, but any time there is in-cloud lightning, there is a chance of ground lightning, so you need to be aware of both,” he said. “Anytime you see lightning or hear thunder, you are close enough to get struck by lightning.

“That’s why we say: Anytime thunder roars, go indoors.”

Thunder and lightning: What is the difference?

Lightning causes thunder, so anytime you hear thunder, lightning is involved even if you can’t see it.

Thunder can help you determine how far away a storm is.

“Every five seconds is one mile away from that lightning,” Vagasky said. “And you can hear thunder for about 8 to 10 miles. If you’re seeing lightning 40-50 seconds before hearing thunder, you are still close enough to be struck by lightning.”

How do you know if the clouds rolling in are, in fact, a thunderstorm?

The shape of clouds can help you identify a developing thunder/lightning storm, Vagasky said.

“If the clouds are getting tall and puffy, like a big head of cauliflower, that’s an indicator that a thunderstorm is developing,” he said. “When a thunderstorm is fully developed, those clouds will flatten out on the top, like an anvil – that is a mature thunderstorm.”

The cloud’s color is secondary to its shape because color depends on the relation to the sun. White puffy clouds that get much darker can also indicate a developing thunderstorm.

A radar image also is a secondary indicator of a storm. Yellow, orange and red colors indicate a storm that is more likely to be a thunderstorm, but lightning can also happen outside those colors, on the storm’s outer boundary.

Vagasky said many weather apps will include lightning data, and you can turn on notifications to be aware when lightning is nearby. But, he warns, those apps rely on having cellular service, which isn’t always available in Colorado’s outdoors.

“A lot of it goes back to being aware of the weather before you start your outdoor activities,” he said. “And then keep an eye on the sky so you can wrap up your activity and get to a safe place if a storm is coming.”

Where is a safe place during a lightning storm?

“There are only two safe places during a thunderstorm: a fully enclosed metal vehicle or a substantial building,” Vagasky said. “There is no safe place outside.”

A substantial building is one with electricity and plumbing. If a substantial building is struck by lightning, the energy will travel through the wires and pipes, keeping you safe. This is why, during a lightning storm, you should not use phones with cords, play video games or use other plugged-in devices, or use plumbing (don’t shower or wash dishes). Also, stay away from windows during a storm.

“A window creates a gap in the wall, so if lightning strikes, it could jump across that gap, and if you’re standing next to it, you could be what it jumps to,” Vagasky said.

A fully-enclosed metal vehicle is important for the same reasons. Electricity travels through the metal body of a car, keeping the occupants safe. Vagasky stresses that the enclosed metal body of a vehicle, not the rubber tires, keeps someone safe. ATVs, golf carts, and soft-top convertibles are not safe places during a lightning storm.

Finding shelter under a tree is also unsafe.

“The big thing we see is people seeking shelter under a tree – flee the tree,” Vagasky said. “Lightning tends to strike tall, pointy and isolated things. A tree is just that. So if you’re standing near that tree, you’re a target for lightning.”

In 2022, three people died from lightning after “riding out the storm under a tree” near the White House. That same year, a mother in Florida was killed by lightning while waiting under a tree for her children outside their school.

Vagasky said the best thing you can do if you are in a lightning storm is immediately head to safety, whether that be your vehicle in the parking lot or miles away at the trailhead.

“In Colorado, we get four to eight cloud-to-ground lightning events per square kilometer per year,” he said. “How big is a square kilometer? It’s 187 football fields put together. So, if there is only a handful of these, your chances of being in one of those spots are very low. So by continuing to move to a safe place, even in the elements, you’re improving your odds.”

What can you do if there isn’t a safe lightning shelter? What about the ‘lightning crouch’ and other options?

The lightning “crouch” – where you crouch down to make your body as small as you can – is no longer recommended, Vagasky said.

“It prevents you from getting to a safe place, and it doesn’t provide any additional safety,” he said.

Another myth is that putting all four limbs on the ground disperses voltage when electricity travels through you. Vagasky references the recent lightning fatality in Colorado.

“That lightning killed 34 cows,” he said. “Lightning kills a lot of animals through ground current because it strikes nearby, travels through the ground and up one set of legs, crosses the body and back through the other set of legs, crossing through all those internal organs. Keep moving toward a safe place.”

And though trees aren’t safe, shorter groves will be safer than tall, isolated trees.

Vagasky also advises that people in groups spread out. By spreading apart, you’ve increased the odds that someone won’t be as affected by a lightning strike and can assist those who were injured.

What do you do if you’re involved in a lightning incident?

“The number one thing is to get help by some means,” Wiktor said. “If you see someone struck by lightning and can do CPR, that could save their life.”

People struck by lightning can suffer cardiac and respiratory issues hours and even days after the event. They can also suffer deep muscle damage that can lead to long-term issues if not properly treated and monitored. Lightning can also damage one’s kidneys and eyes. At his center, Wiktor said that lightning-injured patients undergo an array of tests and monitoring because “the body can be unpredictable after experiencing an electrical surge.”

But, Wiktor stresses, “an ounce of prevention is worth a pound of cure.”