More dreaded than the frosts are the terrible burans or snowstorms, which occur in early spring and destroy thousands of horses and cattle that have been grazing on the steppes throughout the winter.
At Ghazni the snow has been known to lie long beyond the vernal equinox; the thermometer sinks to io° and 15° below zero (Fahr.); and tradition relates the entire destruction of the population of Ghazni by snowstorms more than once.
Although snowstorms are infrequent and snow never lies long on the ground, the average fall of snow for the year amounts to 22.5 in.
The higher summits of the Cordilleras afford a larger and more continuous supply of water, and so dependent are the people in the cultivated river valleys on this source of water supply that they watch for snowstorms in the Cordilleras as an indication of what the coming season is to be.