The temperature of the air in the lightning channel may reach as high as 50,000 degrees Fahrenheit, 5 times hotter than the surface of the sun. Immediately after the flash, the air cools and contracts quickly. This rapid expansion and contraction creates the sound wave that we hear as thunder.

The initial sound reaches the ear with a loud bang, crack, or snap. As shock waves propagate away from the path of the lightning bolt, they are distorted, becoming stretched and elongated. The sound is more muted. Other shock waves from more distant locations arrive at the listener.

Thunder is the loud noise that comes right after lightning. It also can refer to a loud, booming sound, or mean to move heavily but quickly. Thunder is made up of the rumbles and cracks accompanying lightning during a thunderstorm.

Thunder is the sound produced by the rapid heating of air by a lightning strike. The word thunder is derived from the 'Thor', the Norse god of thunder, known for his ability to forge thunderbolts. Essentially, thunder is the sound produced by lightning.