FactSentinel

Lightning heats the air in its path to roughly 30,000 degrees Celsius (about 54,000 degrees Fahrenheit), which is about five times hotter than the Sun's visible surface, or photosphere, at roughly 5,500 degrees Celsius. The figure comes from spectroscopic measurements of lightning channels, which analyze the light emitted by the superheated gas and reveal its temperature. Laboratory spark experiments and atmospheric physics models support the same range.

The heating happens because a lightning stroke carries a huge electrical current, often around 30,000 amperes and sometimes far more, through a channel only a few centimeters wide. The current ionizes the air into plasma and heats it in a few microseconds. The rapid expansion of the superheated air creates a shock wave that travels outward and becomes the sound of thunder. This explains why thunder is so sharp and loud close to a strike.

A few clarifications help avoid confusion. The comparison applies to the Sun's surface, not its core, which reaches about 15 million degrees Celsius. The extreme temperature is also confined to a very narrow channel and lasts only a fraction of a second, so the total heat energy released is modest compared with a sustained heat source. That brevity explains why lightning can ignite fires, fuse sand into glass tubes called fulgurites, and cause serious injury, yet does not heat the surrounding atmosphere in any lasting way.