Overpressure is the pressure caused by a shock wave over and above normal atmospheric pressure. The shock wave may be caused by sonic boom or by explosion, and the resulting overpressure receives particular attention when measuring the effects of nuclear weapons or thermobaric bombs.

A nuclear bomb can produce an overpressure corresponding to 278 decibels. 200 decibels is enough to cause instant death. 278 decibels is about 10 million times greater sound intensity.