Above average temperatures may have contributed to Washington DC's deadly lightning strike on 4 August.
Climate change is increasing the likelihood of lightning strikes across the United States, scientists say.
The warning comes after a deadly lightning strike hit Washington DC last Thursday (4 August 2022), killing three people and leaving one other in critical condition.
What caused the deadly lightning strike in Washington DC?
Last week's hot, humid conditions in Washington DC were primed for electricity. Air temperatures topped out at 34C. This is 3C higher than the 30-year normal maximum temperature for this time of year, according to the National Weather Service.
More heat can draw more moisture into the atmosphere, while also encouraging rapid updraft - two key factors for charged particles, which lead to lightning.
Global warming could increase the number of lightning strikes
In 2014, a key study released in the journal Science warned that the number of lightning strikes could increase by 50 per cent in this century in the United States. For each 1C of warming, a 12 per cent rise in the number of lightning strikes could occur, according to the study.
Fast-warming Alaska has seen a 17 per cent rise in lightning activity since the cooler 1980s. And in typically dry California, a siege of 14,000 lightning strikes during August 2020 sparked some of the state’s biggest wildfires on record.
Because heat and moisture are often needed to make lightning, most strikes happen in the summer. In the United States, the populous, subtropical state of Florida sees the most people killed by lightning.
Beyond the United States, there is evidence that lightning strikes are also shooting up in India and Brazil.
Three people were killed by the Washington DC lightning strike
Two men and two women were struck by lightning on Thursday while visiting Washington's Lafayette Square, just north of the White House.
During a violent, afternoon thunderstorm, lightning hit near a tree that stands metres away from the fence that surrounds the presidential residence and offices across from the square, which is often crowded with visitors, especially in the summer months.
All four victims sustained critical, life-threatening injuries, and were taken to area hospitals. Two of them later died: James Mueller, 76, and Donna Mueller, 75, from Janesville, Wisconsin, the Metropolitan Police Department reported.
"We are saddened by the tragic loss of life," the White House said in a statement on Friday. "Our hearts are with the families who lost loved ones, and we are praying for those still fighting for their lives."
Later on Friday a third victim, a 29-year-old male, was pronounced dead. Further details on the victim were being withheld until the next-of-kin were notified.
It is still rare to be hit by lightning in the US, experts say
But even as lightning strikes increase, being hit by one is still extremely rare in the United States, experts say. Roughly 40 million lightning bolts touch down in the country every year, according to the Center for Disease Control - with the odds of being struck less than 1 in a million.
Among those who are hit, about 90 per cent survive the ordeal, the CDC says. The country counted 444 deaths from lightning strikes from 2006 through to 2021.