In a remarkable discovery, scientists have confirmed the longest lightning strike ever recorded — a single bolt that traveled an astonishing 829 kilometers (515 miles) from Dallas, Texas, to Kansas City, Missouri. This extraordinary lightning event, classified as a “megaflash,” has captured global attention for both its scale and scientific significance.
The record-breaking lightning strike occurred during a severe storm in October 2017, but the findings were only recently published in the Bulletin of the American Meteorological Society (BAMS) on July 31, 2025. The bolt took 7.39 seconds to travel across the sky, maintaining its intensity across that vast distance — a feat never observed before.
“Megaflashes” are rare and powerful types of lightning discharges that span exceptionally large distances. According to physicist Michael Peterson from Atlanta, only 1 in 1,000 lightning strikes becomes a megaflash. These phenomena not only connect clouds over hundreds of kilometers but can also make contact with the ground, often causing serious damage to tall trees and even triggering wildfires. While a typical lightning bolt may last a few microseconds, megaflashes persist for at least 100 milliseconds, making them significantly more intense and dangerous.
Prior to this, the longest recorded lightning strike happened in 2020, stretching 768 kilometers across Mississippi, Louisiana, and Texas. Even earlier, a lightning bolt in 2018 traveled 709 kilometers through parts of Brazil and Argentina, though it lasted an extraordinary 17 seconds. That duration was matched in 2020, when another megaflash illuminated the skies over Uruguay and Argentina for 17.1 seconds, setting the record for the longest-lasting lightning event.
The latest record not only surpasses previous distances but also deepens scientists’ understanding of extreme weather phenomena. Research is ongoing to better understand how such massive bolts form within cloud systems and what atmospheric conditions allow them to stretch so far.
This new record showcases the immense power and complexity of nature — a reminder of just how much remains to be discovered above our heads.