The redistribution of impurity due to secondary convection in a cylindrical floating zone is studied using a control volume-based numerical technique. The flow is induced by differential rotation of the feed rod and crystal. Attention is focused on the transient stage of segregation. It is found that the transient length increases with the strength of secondary convection. A maximum in radial segregation is found to occur when secondary convection creates radial gradients but is not strong enough to homogenize them. The influence of cellular structure on the transient length is also examined.