The concept of progression is applicable to how students' geographical understanding can advance over a period of time, and how courses can be designed to facilitate such advances. Understanding is a product of experience, ideas and mental processes, and the interrelationships between them. The ideas which are most characteristic of geographical understanding are those associated with its distinctive perspectives of place, space and environment. However, geographical understanding also makes use of ideas which have been developed in other disciplines, and important ideas which are common to most disciplines. Planning for progression should take account of practical and theoretical considerations. Progression involves a wide range of different qualities/dimensions which are illustrated here in relation to the theme of weather and climate. (Contains 4 figures.)