Did you know lightning can be hotter than the Sun – but by how much?

A lightning strike can briefly heat the air around it to temperatures several times hotter than the visible surface of the Sun.

When lightning travels through the atmosphere, it creates a narrow channel of extremely hot, electrically charged gas called plasma.

The intense electrical discharge heats the surrounding air to around 30,000°C. That is roughly five times hotter than the Sun’s visible surface.

This does not mean lightning produces more energy than the Sun. The lightning channel is tiny and remains extremely hot for only a fraction of a second, while the Sun continuously releases enormous amounts of energy across its vast surface.

Why does lightning get so hot?

Air normally resists the movement of electric charges. During a lightning strike, the powerful electrical discharge heats the air and strips electrons from its atoms, turning the air along its path into plasma.

The sudden heating also makes the air expand rapidly. This creates a powerful shock wave that travels through the atmosphere as thunder.

When lightning strikes a tree, the extreme heat can rapidly turn water inside the tree into steam. The sudden expansion can strip bark from the tree and, in some cases, cause parts of it to split or even explode.

How do scientists estimate the temperature?

Scientists can estimate the temperature of lightning by studying the light it produces and the behaviour of the plasma channel.

They can also analyse the wavelengths of light emitted during a strike.

Scientists determine the Sun’s surface temperature in a different way. They analyse the Sun’s spectrum and use the characteristics of its emitted radiation to estimate its temperature.

So, the next time you see a flash of lightning, keep in mind that, the air around that tiny channel can become far hotter than the visible surface of the Sun.

The Sun remains vastly more powerful overall but lightning wins the temperature comparison.