According to a recent study published in the Bulletin of the American Meteorological Society, or BAMS, the world record has been set for a lightning bolt: 199.5 miles! The record bolt flashed over Oklahoma on June 20th, 2007 and crossed over much of the state.
According to the University of Florida's Lighting Research Group, the average lightning bolt length is just 5 miles long. That makes the record bolt stretch from downtown Raleigh almost to Charleston, SC!
The world's longest flash is also documented in the article. It happened in Provence-Alpes-Cte d'Azur, France on August 30, 2012. That flash lasted 7.74 seconds!
Both were detected using extremely sensitive radio receivers. It works the same way that static can interfere with an AM radio signal. Scientists triangulate those radio interferences and determine when, and where, the strikes occur.
Both records were certified by the World Meteorological Organization.
By the way, it's been a terrible year for lightning-related deaths. According to the National Weather Service 35 people have died due to lightning-related injuries, with two of those here in NC. That makes it the deadliest year for lightning deaths in the US since 2007.