text: which comes first lightning or thunder?explain why?   the lightning comes first.  lightning is 5 times hotter than the surface of the sun, so the air around it is superheated and expands rapidly, creating almost a vacuum.  as the lighning dissapates, the pressure around the area immediately fills the vacuum due to the great pressure gradient.  whenever there is a sudden change in pressure, shock waves are created that make audible sounds.  just as in a gun shot or a balloon popping, the sudden increase and decrease in pressure cause a loud shockwave that can be heard for miles.