The paper discusses wind tunnel studies on the effect of the mean speed profile of the on-blowing wind on the rate of air flow through cross ventilated enclosures. The mean wind speed profiles represented by a simple power law, with exponents ranging between 0.12 and 0.4, were generated in the test section of the tunnel. A model of a room was exposed to various wind profiles, and corresponding rates of air flow were measured. It was observed that average wind speed through the window decreases with an increase in the power-law exponent. An empirical relationship was also derived between the power-law exponent, the average wind speed through the inlet and the average outdoor wind speed at the window level.