This paper is a report on the state of knowledge of sonic‐boom phenomena. The pressure buildups in the transonic‐speed range and the lateral extent of the pattern in steady flight for quiescent atmospheric conditions are described. Also discussed are recent data from flight‐test studies relating to atmospheric dynamic effects on the sonic‐boom signatures. The acceleration and lateral‐spread phenomena appear to be fairly well understood and predictable for current and future aircraft. Variations in the sonic‐boom signature as a result of the effects of the atmosphere can be expected during routine operations. From the data evaluated to date, very similar variations in pressure signatures are noted for both fighter and bomber aircraft.