IOWA — A thunderstorm is not a thunderstorm without lightning, and even though more people fear tornadoes, lightning is far more frequent and results in far more deaths per year than tornadoes. But nearly all deaths from lightning are preventable.

How does lightning form?

Inside a cloud are negative and positive charges. Because winds travel in different directions at varying speeds these charges can get separated in a way that negative charges settle at the bottom of the cloud and positive charges rise to the top of the cloud. On the ground, plants and objects are positively charged. When the difference between the negative charges in the cloud and the positive charges on the ground becomes too great the air rapidly heats and expands causing a bright flash and loud rumble.

U.S. Lightning fatality data

Over the past 10 years, 231 people have died after being struck by lightning in the U.S. When broken down by gender, 49 were female and 182 were male. Of the 231 people killed, 60 people, or about 25% were killed while near, in, or under a tree.

Lightning deaths in Iowa vs other states

There have been 2 lightning-related deaths in Iowa over the past 10 years. They both occurred in 2015. On May 4, 2015, 35-year-old, William Clevenger was struck by lightning while rounding up cattle on a horse in Muscatine county. A little over a month later, on June 20, 2015, 42-year-old Rebecca McCarty was struck while camping in Linn county.

States along the coast of the Gulf of Mexico historically have the highest number of lightning-related deaths. Just in the past 10 years, Florida has seen 52 lightning-related deaths, while the next highest is Texas with 21.

Check out Lightning Myths vs Facts from the NWS

FILE: Lightning strikes as a violent thunder storm approaches the area Aug. 16, 2004 in Ft. Myers, Florida. (Photo by Mark Wilson/Getty Images)

Why is lightning so dangerous?

When lightning strikes, the air is heated to more than 50,000°F which is five times hotter than the surface of the SUN! Not only that, but a huge amount of energy travels through your body which can result in cardiac arrest and irreversible brain damage. Only about 10% of people struck are killed, but the other 90% are left with varying degrees of disabilities.

Preventing lightning deaths

You may have heard the phrase, “When Thunder Roars, Go Indoors”. If thunder can be heard, lightning is close enough to strike. While most lightning will strike within the thunderstorm it is associated with, lightning strikes can still occur up to 10 miles from the center of the thunderstorm.

If traveling, stay in your car. Even if your car is struck by lightning, it will still protect you from the worst of the lightning’s effects. Unfortunately, the car doesn’t always make it.

If at home, go inside and close all windows and doors.

If outdoors, find the closest building. A bathroom at a park offers way more protection than a dugout, a gazebo/pergola/tent, or playground equipment. The charges that produce lightning try to find the closest object to discharge the imbalance it is experiencing, which tends to be something tall, so sheltering under an open shelter or tree will actually increase your chances of being struck.