In San Francisco the thermometer seldom falls below 45º in the winter, the average for the season being 51º. Perhaps in January or February the sidewalks may be white with frost in the mornings, or hail may fall during some cold rain-storm. Once in five years or so, enough snow falls to make children go wild with delight over a few snowballs which are very soon melted. People can be comfortable the year round without fires, and the clear, bright winter days with soft air and warm sunshine are always pleasant enough to spend outdoors. This ocean climate, due to the warm sea air, is enjoyed by the counties facing the coast and San Francisco Bay. In the valleys of the interior white frosts are frequent, and thin ice forms on the wayside puddles. Once in a while killing frosts destroy fruit blossoms and cut down the garden flowers and vegetables, but seldom do more damage. [Illustration: "EL CAPITAN" (3300 feet in height).] [Illustration: YOSEMITE FALLS.] In mountain regions, above five or six thousand feet, the very cold winter lasts six or seven months. Snow falls almost constantly and drifts to a great depth. Small lakes are frozen and buried in snow, and the trees are bent and weighed down with ice and sleet. Many of the wild animals come down to the foot-hills below the snow-line to spend the winter; but the bear curls himself up in his warm cave and sleeps through the cold months. In this snowy zone of the Sierras, about thirty miles wide, winter lasts from the first snowfall, about the end of October, to the late spring of June. Then July and August are months of glorious weather, with clear, dry air and a cloudless sky. During the day the temperature of about 80 degrees melts much snow, and the rivers carry it away in rushing torrents and falls of icy water. In September the frost turns the leaves of all but the evergreen trees beautiful colors of red and yellow. Indian summer comes during September and October, when the days are sunny and warm, and then the long winter sets in again. Peaks above eight thousand feet are snow-clad on their crests and along their sides by deep drifts the year round. Along the Pacific coast in summer cool sea-winds, called trade-winds, blow in from the ocean, and 60 degrees is the average temperature. The farther you go inland from the coast, the hotter it gets, and the heat is very great in the interior of the state. In the San Joaquin and Sacramento valleys it is often over 100 degrees in the shade, though this dry heat is not hard to bear, and the nights are always cool enough for one to sleep in comfort.