ABSTRACT
Beyond the limits of the swing of the equatorial rainfall belt, at the latitudes in which the trade winds blow throughout the year, lie the world’s greatest deserts, where the annual precipitation is less than 25.5 cm (10 in.). Hot deserts, such as the Sahara and Kalahari, have no cold season but, in the so-called ‘cold deserts’ like the Gobi and Great Basin, one or more of the winter months has a mean temperature below 6°C (43°F).
