ABSTRACT
Seasonality in temporal terms has been strongly demonstrated in the preceding chapters in a number of histograms indicating the months of maximum and minimum values. In regional terms seasonality has been expressed by noting the annual ranges of various climatic values. A number of attempts have been made to delimit climatic regions in West Africa. Contrasting situations are obviously indicated, perhaps seemingly thereby supporting the commonly held view that the climate of West Africa comprises two seasons, wet and dry. The Inter-tropical Discontinuity (ITD) lies far south in West Africa, so that the greater part of the region is under the influence of the northern, continental Saharan airmass. Just south of the ITD and in a zone some 600 km wide, north to south, the weather is much the same as in December, though the winds are markedly from the west. The movement of the ITD is, of course, very variable within the overall repeating pattern.
