As ozone plays a central role in stratospheric chemistry a complete climatology of the molecule is essential. Due to the increased amount of ozone data available in recent years, there are several aspects of the measurements that have only recently become clear. These are (i) high latitude ozone minima at about 30 km over both the Arctic and Antarctic, (ii) diurnal variations of ozone, and (iii) the advantages of dynamically based coordinates. Although previously seen as a weak feature in satellite data, it has now become clear that minima in ozone occur at about 30km in both regions during much of the year. The more extensive ozone database has also allowed the determination of ozone diurnal variations, particularly from satellite data. Finally, as ozone in the lower and middle stratosphere is strongly influenced by transport and that transport is frequently zonally asymmetric, a climatology of ozone based on latitude-pressure coordinates should be reviewed. These three aspects will be explored using published material supplemented by results from the Met. Office three-dimensional model. It is argued that all three aspects should be included in an ozone climatology. (C) 1998 COSPAR. Published by Elsevier Science Ltd.