In section 2, the physical significance of the time-averaged equations of motion is discussed. In the time averaged vorticity equation, the terms expressing the vertical transport of vorticity, the dissipation of vorticity due to friction, and so on, become important in their magnitude. As for the time-averaged thermodynamic equation, the magnitude of the term expressing the heat transfer due to horizontal disturbances is about the same order as that due to mean horizontal velocity. On the contrary, the heat transfer due to vertical disturbances is extremely small as compared with that due to mean vertical velocity.In section 3, we compute the mean vertical velocity and the mean supply of heat during the rainy season. An interesting feature in the patterns is the existence of a marked zone of cooling and of a pronounced downward motion near the so-called Okhotsk high.In section 4, the mean stream function and the mean velocity potential are obtained. Utilizing the mean velocity potential, the vertical distributions of divergence at the southwestern part of the Okhotsk high are analyzed.