UARS MLS measurements of lower stratospheric ClO during the 1992--93 and 1993--94 Arctic winters are presented. Enhanced ClO in the 1992--93 winter was first observed in early December, and extensively during February when temperatures were continually low enough for PSCs. Sporadic episodes of enhanced ClO were observed for most of the 1993--94 winter as minimum temperatures hovered near the PSC threshold, with largest ClO amounts occurring in early March after a sudden deep cooling in late February. ¿ American Geophysical Union 1995