Where lightning hit the most in the U.S. in 2021

Between an active monsoon and hurricane season, the sky unleashed an unusual amount of lightning in the Southwest, Northeast and Gulf Coast.

Change in lightning strikes,

2015-2020 vs. 2021

Half as many

No change

More than 2x

500 MILES

Note: Map shows 2021 data compared to the

stroke density average for 2015-2020. Comparable

data for Alaska and Hawaii is not available.

Change in lightning strikes

in 2021 vs. 2015-2020

Half as many

More than 2x

No change

500 MILES

Note: Map shows 2021 data compared

to the stroke density average for 2015-2020.

Comparable data for Alaska and Hawaii is not available.

Change in lightning strikes in 2021 vs. 2015-2020

Half as many

More than 2x

No change

Seattle

Boston

Minneapolis

Detroit

New York

San

Francisco

Chicago

Salt Lake

City

D.C.

Denver

St. Louis

Los

Angeles

Atlanta

Dallas

New Orleans

250 MILES

Houston

San

Antonio

Miami

Note: Map shows 2021 data compared

to the stroke density average for 2015-2020.

Comparable data for Alaska and Hawaii is not available.

Change in lightning strikes in 2021 vs. 2015-2020

Half as many

More than 2x

No change

Seattle

Boston

Minneapolis

Detroit

New York

Chicago

San

Francisco

Salt Lake

City

D.C.

Denver

St. Louis

Los

Angeles

Atlanta

Dallas

New Orleans

Houston

250 MILES

San

Antonio

Miami

Note: Map shows 2021 data compared to the stroke density average

for 2015-2020. Comparable data for Alaska and Hawaii is not available.

Lightning affects all regions of the United States, and has been responsible for more than 400 deaths and thousands of injuries over the past 16 years.

Some areas are more susceptible to lightning than others, though, based on geography and weather. If you were living near the U.S. Gulf Coast or Southwest in 2021, you were no stranger to lightning. Between an active monsoon and an abnormally high number of tropical storms, streaks of energy raced through the atmosphere in record numbers. Data shows that those regions experienced more lightning last year than in the previous five years, on average.

Yet lightning and lightning fatalities can occur in less popular spots. On Thursday, at least two people died in a lightning strike in Washington, D.C. — potentially the first lightning deaths in the nation’s capital since 1991. So far in 2022, 11 people have died of lightning strikes.

This year follows a record low year for lightning deaths. In 2021, the United States experienced 11 lightning-related fatalities. The decrease may be attributable to improved forecasts and awareness, or potentially more people quarantining indoors because of the pandemic, but lightning strike data can also provide clues.

“When you look at lightning counts, you get a feel for how stormy the year was, how much instability was there in the atmosphere, how much precipitation was there,” said Chris Vagasky, a meteorologist with Vaisala, a company that has operated a network of lightning sensors in the U.S. for almost 40 years and globally for 10 years.

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Lightning is a large natural spark of electricity, caused by an imbalance of electrical charges in the atmosphere. Most lightning is formed from thunderstorm clouds, which develop when warm, moist air rises into cold air, often during warmer seasons. A storm’s lightning flash rate is often related to a storm’s severity, or how deep the thunderstorm cloud is.

Vaisala sensors detected more than 194 million lightning events in 2021, about 24 million more than in 2020, which was an extremely low year. Despite the increased activity, the nation’s lightning in 2021 was below recent averages for the second year in a row. Thirty-two of the Lower 48 states experienced lower-than-normal activity. But although the exceptions were few, they were grand.

Top lightning spots

Vaisala data indicates that the United States experienced the second-highest lightning count worldwide — not necessarily surprising, given the country’s size and the fact that it typically is one of the stormiest locations in the world because of extreme north-south temperature contrasts.

Number of lightning strikes, 2021

0

200+

500 MILES

Note: Number of strikes is for each

2-by-2-km grid. Comparable data

for Alaska and Hawaii is not available.

Number of lightning strikes, 2021

0

200+

500 MILES

Note: Number of strikes is for each 2-by-2-km grid.

Comparable data for Alaska and Hawaii is not available.

Number of lightning strikes, 2021

0

200+

Seattle

Boston

Minneapolis

Detroit

New York

San

Francisco

Chicago

Salt Lake

City

D.C.

Denver

St. Louis

Los

Angeles

Atlanta

Dallas

250 MILES

Houston

New Orleans

San Antonio

Note: Number of strikes is for each 2-by-2-km

grid.Comparable data for Alaska and Hawaii is

not available.

Miami

Number of lightning strikes, 2021

0

200+

Seattle

Boston

Minneapolis

Detroit

New York

Chicago

San

Francisco

Salt Lake

City

D.C.

Denver

St. Louis

Los

Angeles

Atlanta

Dallas

New Orleans

Houston

250 MILES

San

Antonio

Note: Number of strikes is for each 2-by-2-km grid.

Comparable data for Alaska and Hawaii is not available.

Miami

In 2021, the top two states to experience lightning were Texas and Florida. They often take the top spots because of their relatively tropical and less stable atmospheres, which make thunderstorms more common than in other parts of the nation. Texas and Florida experienced the most lightning in 2020 as well.

In a somewhat unexpected shift, Louisiana experienced the third-highest lightning counts in the United States last year — topping traditional lightning powerhouses such as Oklahoma, Kansas and Missouri. The activity probably was tied to the active hurricane season, which was headlined by Category 4 Ida.

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“There were several systems that tracked right along the Gulf Coast or made landfall right around the Louisiana area,” said meteorologist Elizabeth DiGangi. “A lot of lightning you may see in tropical systems is in the outer rain bands. Even something that made landfall in the Houston area would have ended up providing a good bit of rainfall and lightning to Louisiana as well.”

Meanwhile, the Southeast and Central Plains experienced a quieter-than-normal severe weather season in the spring. According to Vaisala’s data, Oklahoma experienced fewer than 10 million lightning events — about 1 to 2 million fewer than normal.

“Oklahoma, Kansas and Missouri all moved down a spot this year. They were all lower than what you would normally expect to see for lightning, and there was less severe weather reported in these areas,” Vagasky said. “It’s kind of another down year for tornadoes up until December, unfortunately.”

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On Dec. 10, a tornado outbreak ravaged the Southeast from Arkansas to Kentucky, where more than 70 people died. Then, on Dec. 15, a line of violent thunderstorms and tornadoes, or a derecho, unleashed damage in seven states in the central United States.

Sensors detected more than 3 million lightning events in December 2021, a bit more than normal for the month, Vagasky said.

Unusual lightning

Most notable was that last year marked the return of an active monsoon season in the Southwest. After 2020’s “non-soon,” 2021 came back with a roar — and with lightning. Vaisala data showed Arizona experienced around 3.5 million lightning events — 2 million more than in the previous year. Southern California in the U.S.-Mexico border area experienced more than twice the average number of lightning events.

“In both 2019 and 2020, the monsoon basically failed to develop, for other large-scale atmospheric reasons. It was probably some much-needed relief this year for the area, but that did mean that there was more lightning for sure in that area than there was in previous years,” said DiGangi, a lightning researcher at Earth Networks.

Earth Networks operates a global network of lightning ground sensors that provide data to government entities, emergency management organizations, aviation companies and other private-sector entities. The company also detected a slight increase in lightning counts from 2020 to 2021 with their sensors.

The 2021 Southwest monsoon is in full force in Arizona

In addition to lightning counts, DiGangi and her colleagues at Earth Networks count thunder days and thunder hours per year to measure the storminess of an area. A thunder day is one on which a person at a given location can hear thunder caused by a nearby storm.

Thunder is created when lightning travels through the atmosphere, heating the air to 50,000 degrees. When the air cools shortly after the lightning flash, the rapid expansion and contraction creates a sonic discharge, the rumble of thunder. The thunder day metric relies less on the number of lightning flashes detected and more on the convection present in a certain mile radius.

In 2021, Earth Networks counted more than 7,800 thunder days across the United States — a 4 percent increase from 2020. Similar to the Vaisala lightning data, Texas, Florida and Louisiana experienced the most thunder days. New Mexico, while not ranking in the top 10 for lightning counts, did have the ninth-highest number of thunder days in the nation last year.

“You can get a sense of what locations experience a lot of active convection versus places where it’s less common,” DiGangi said. “It tells you more about if the location experiences storms, which is our kind of primary concern in a lot of ways, because it’s the storm bringing the rain, it’s the storm bringing the wind, the severe events and, of course, the lightning.”

In addition to the Southwest, other states across the northern United States experienced anomalous amounts of lightning and thunder days. Michigan registered an unusually high number of lightning strikes for 2021, thanks to a slew of summer storms every couple of weeks.

“In 2020, Michigan had what we think was their biggest year, and then that was surpassed [in 2021],” Vagasky said.

Many northeastern states, such as Pennsylvania, New Jersey and Massachusetts, also experienced higher-than-normal numbers of lightning events. Vagasky cites abundant tropical storm activity as well as the multiple active weather patterns traveling from the Great Lakes region.

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Although the nation’s overall lightning activity was below average again, researchers do not think the current lightning trends are necessarily tied to climate change — at least not in the United States. Vaisala data over 30 years shows that trends in the United States have been relatively consistent, with annual ups and downs based on weather patterns.

“In a broader sense, with the climate warming up, we would have more updrafts and we would have more thunderstorms,” said Rachel Albrecht, a professor and lightning researcher at the University of São Paulo. “But it is not homogeneous around the globe.”

This year, the Arctic experienced more lightning than it did from 2012-2020 combined, according to Vaisala data. Lightning in the Arctic is particularly concerning because it indicates an increase in warm and moist air intrusions into the high latitudes. Vagasky said background warming helps to drive some of these weather patterns.

“We know that climate is changing faster in the Arctic than anywhere else on the Earth,” Vagasky said. “Monitoring these trends really helps us get a good feel for exactly what’s happening up there.”

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About this story

Lightning data is from Vaisala.

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