The longest lightning bolt ever recorded stretched 477 miles across three U.S. states in a single, continuous flash.

On April 29, 2020, a single lightning flash spanned a horizontal distance of 477.2 miles (768 kilometers) across the southern United States. This extraordinary event was officially certified by the World Meteorological Organization (WMO) in early 2022 after extensive data analysis. The bolt originated near the Texas-Louisiana border and extended all the way to Mississippi, passing through three states in total.These massive electrical discharges are known as "megaflashes" and occur within Mesoscale Convective Systems (MCS). Unlike common cloud-to-ground lightning that lasts less than a second, megaflashes can persist for several seconds and travel hundreds of miles horizontally. This record-breaking flash lasted approximately 8.5 seconds as it ripped through the sky.Modern satellite technology has revolutionized how we track these events. Researchers used data from the Geostationary Operational Environmental Satellite (GOES-16) to measure the flash from space. This technology allows scientists to observe the full extent of a bolt, which is often impossible to track using ground-based sensors alone.The previous record was held by a 440-mile flash in Brazil recorded in 2018. These findings highlight the extreme scale of electrical activity in large storm complexes. Understanding megaflashes is critical for aviation safety and meteorological modeling, as they demonstrate that lightning can strike far from the center of a storm.