ABSTRACT
The occurrence of rain in Mediterranean climates is usually associated with the passage of cyclonic storms and its seasonal incidence corresponds to the equatorward migration of the westerly circulation in which these occur, i.e. to the winter months. Clearly eastern or western marginal situation must be a fundamental criterion of subdivision of these climates. In the simplest form the warm-temperate climates derive their summer influence from the east and their winter influences from the west; summer is therefore continental on western margins and marine on astern; winter conversely is marine on western margins and continental on eastern. The Mediterranean climates lie near the limit of the cyclonic rains and the precipitation in consequence is somewhat unreliable. Southwards and eastwards the boundary is vague, the Mediterranean climates grading in this direction imperceptibly into desert and steppe. The climate of the Iberian Peninsula is a curious variety in which the Mediterranean type is struggling against the effects of conti-nentality.
