How Fast Is Lightning Return Stroke?

The visible lightning return stroke travels upward at about 100,000 km/s — one-third the speed of light. It completes in under 0.2 milliseconds, far too fast for human perception. The bolt itself is briefly hotter than the surface of the Sun.

A lightning bolt is briefly hotter than the surface of the Sun — about 30,000 K — for a fraction of a millisecond.

• Channel briefly hotter than the Sun's surface
• Heats air to 30,000°C in microseconds