Answer. Thunder is caused by the rapid expansion of the air surrounding the path of a lightning bolt. ... As lightning connects to the ground from the clouds, a second stroke of lightning will return from the ground to the clouds, following the same channel as the first strike.

Why is thundering so much?

Why is thunder so loud? It's because the amount of electrical energy that flows from the cloud to the ground is so enormous: it's like a very big waterfall of electricity. The louder the sound that you hear, the closer you are to the lightning. Light travels through air much faster than sound.

What causes thunder without lightning?

No, it is not possible to have thunder without lightning. Thunder starts as a shockwave from the explosively expanding lightning channel when a large current causes rapid heating. However, it is possible that you might see lightning and not hear the thunder because it was too far away. ... Thunder is caused by lightning.