U.S. lightning deaths hit record low in 2021, while the Arctic saw far more bolts than usual

• 11 Americans were killed by lightning in the U.S., the National Lightning Safety Council said.
• The number of lightning strikes reported in the Arctic was unusually high in 2021.
• If you hear thunder, go indoors. If you hear thunder, you’re within striking distance of lightning.

2021 was a record year for lightning, both in the U.S. – where deaths reached an all-time record low – and in the northern reaches of the Arctic, which saw a bonanza of bolts last year. It was also a bounce-back year for lightning worldwide, following a 2020 drop due to the COVID-19 pandemic. 

Indeed, even while the number of lightning strikes in the U.S. increased last year over 2020, only 11 Americans were killed by lightning in the U.S., the National Lightning Safety Council said. The previous low was 16 in 2017.

An average year, based on data from 2011 to 2021, sees 23 lightning deaths.

“This new low of 11 lightning deaths is dramatically fewer than the 432 Americans killed by lightning in 1943,” said John Jensenius, a lightning safety specialist with the safety council. 

“That’s a very good sign that the work we’ve been doing on educating people on the dangers of lightning has been working over the years," he said. 

He attributes the new low to increased awareness efforts, such as lightning safety campaigns and readily accessible weather information, such as smartphone apps. If people are more aware of the danger, he said, “and they have the technology to see that danger approaching, that’s going to lead to a reduction in lightning fatalities."

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The sharp drop in lightning deaths over the past 75 years also "coincides with a shift in population from rural to urban regions," wrote meteorologist Ron Holle, also with the safety council, in an article in the Journal of Applied Meteorology.

In the 1940s, "there were many, many more small farmers who were out working in fields," which meant many more chances to be struck by lightning, Jensenius told USA TODAY in 2017.

Arctic sees spike in lightning strikes

At the same time, the number of lightning strikes reported above the 80 degree north latitude line in the Arctic was unusually high in 2021. 

While no one was killed or injured there, nearly double the amount of lightning occurred in those northern reaches than in the previous nine years combined. Vaisala, a company with a global lightning detection network, reported 7,278 lightning strikes in that region of the Arctic in 2021.

Vaisala concluded that’s 91% more than all the lightning measured in the region between 2012-2020 combined.

Researchers say warming temperatures are to blame. 

Lightning increases in the Arctic closely mirror increases seen in warming temperatures, said Robert Holzworth at the University of Washington. He led a team that published a study on Arctic lightning in March 2021, using decades of global lightning data from the World Wide Lightning Location Network. 

Looking at lightning during the summer months of June, July and August over 10 years, they concluded lightning strokes above 65 degrees north latitude increased by a factor of three, even accounting for increased efficiencies in detection.

Summer lightning in the Arctic showed the same pattern as global trends in warmer average temperatures, he said. “We were able to track that and show the years when the temperature was a little higher, there was a little more lightning, and in the years when it was lower, there was a little less lightning.”

That’s not the only way lightning may be connected to human activities.

COVID lockdowns reduced lightning activity in 2020

Researchers studying aerosol emissions released a study last year showing the reduction in travel and emissions as the COVID lockdowns took hold in 2020 caused a drop in aerosols.

In December, a research group at the Massachusetts Institute of Technology published a paper concluding the reduction in aerosols resulted in an almost 8% drop in lightning activity during the 2020 lockdowns. 

“When COVID-19 led to lock-downs, there was a reduction in pollution everywhere,”  Yakun Liu, a meteorological researcher at MIT, stated in a news release.

Fewer aerosols mean fewer of the particles that generate the electrical charges inside storms that lead to lightning, according to their research. 

Vaisala’s annual report showed an increase in lightning in 2021.

Lightning safety tips

If you hear thunder, go indoors. If you hear thunder, you’re within striking distance of lightning.

Always check the weather when you’re going to be outside for a long period of time. Have a plan for seeking shelter. 

Indoors, stay away from all electrical appliances, lighting, electric sockets and plumbing. If no secure shelter is available, a vehicle is a potential second choice — but avoid touching the steering wheel, ignition or radio. The metal is what makes the car or truck safe, not its rubber tires.

As a last resort, if you're trapped with no shelter option, avoid open fields and beaches, trees and light poles. Avoid metal fences and bleachers and unprotected open buildings such as pavilions.

If someone is struck, call 911, begin first aid and CPR if you’re trained. Use an automatic external defibrillator if available.