Turbulence data obtained from over 100 aircraft penetrations of isolated, nonprecipitating cumulus clouds are used to derive statistical parameters associated with the transport of ozone to and from the underlying boundary layer. The parameters are determined by the difference in ozone concentration between the cloud layer and boundary layer, ΔO3. The total cloud flux of ozone, defined as the transport across a horizontal plane within a cloud due to mean and turbulent cloud motions, is given by (-1.2 ¿ 0.2)ΔO3, where is the cloud vertical velocity averaged over an observing period. Cloud turbulence contributes about 30% to the total cloud flux.