ABSTRACTAltitudinal gradients of temperature vary in many different ways, notably according to the time periods considered, but also to such things as differences in topography, synoptic conditions, climatic regions, soils and vegetation cover. This study attempts to separate out the effects due to varying synoptic conditions and different climatic regions, primarily within Great Britain but referring also to southern Norway. Altitudinal gradients of maximun, mean and minimum temperatures react differently to these various influences.