GENEVA: A single flash of lightning in the United States nearly two years ago cut across the sky for nearly 770 kilometres, setting a new world record, the United Nations said on Tuesday.

The new record for the longest detected megaflash, measured in the southern US on April 29, 2020, stretched a full 768 kilometres, or 477.2 miles, across Mississippi, Louisiana and Texas.

That is equivalent to the distance between New York City and Columbus, Ohio, or between London and the German city of Hamburg, the UN’s World Meteorological Organisation (WMO) pointed out in a statement.

That lightning bolt zig-zagged some 60 kilometres further than the previous record, set in southern Brazil on October 31, 2018.

The WMO’s committee of experts on weather and climate extremes also reported a new world record for the duration of a lightning flash.

A single flash that developed continuously through a thunderstorm over Uruguay and northern Argentina on June 18, 2020 lasted for 17.1 seconds — 0.37 seconds longer than the previous record set on March 4, 2019, also in northern Argentina.

“These are extraordinary records from single lightning flash events,” Randall Cerveny, the WMO rapporteur of weather and climate extremes, said in the statement.

“Environmental extremes are living measurements of the power of nature, as well as scientific progress in being able to make such assessments,” he said.