Abstract: The first 200 ns of an air pulsed interelectrode discharge are considered with gas dynamics taken into account. It is this initial stage that is of most importance for determination of the properties of the heating power released in the interelectrode gap. Data are presented on heating of the near-cathode and -anode layers and the gap by the moment when the transient stage in the development of the discharge ends. A spherical expanding shock wave is produced near the cathode.