WMO world record lightning extremes: longest reported flash distance and longest reported flash duration: a WMO committee has judged that the world's longest reported distance (321 km) for a single lightning flash occurred over Oklahoma in 2007, while the world's longest reported duration (7.74 s) for a single lightning flash occurred over southern France in 2012

A World Meteorological Organization weather and climate extremes committee has judged that the world's longest reported distance for a single lightning flash occurred with a horizontal distance of 321 km [...]