Geography of San Francisco

San Francisco is located on the West Coast of the United States at the end of the San Francisco Peninsula that juts into the Pacific Ocean and San Francisco Bay in the city limits. Alcatraz Island, Treasure Island and Yerba Buena Island, as well as smaller island of Alameda, Red Rock Island, and Angel Island is part of the city. In addition, the territory covers the Farallon Islands are uninhabited area 27 miles (43 km) off the coast of the Pacific Ocean. Mainland within the city limits shaped square mile area of ​​7x7 ", although the total area when including waters reach 232 sq mi (600 km ²).

San Francisco is famous for hill-hill. There are more than 50 hills within city limits. Some of the settlements named for the hill where they were built, such as Nob Hill, Pacific Heights and Russian Hill. Near the geographic center of town, just west of downtown, there are a series of low-density hill. Twin Peaks, a pair of hills that exist in one of the highest point of the city, forming the top of the famous sights. San Francisco's tallest hill, Mount Davidson, has a height of 925 feet (282 m) and in 1934 a 103 foot tall cross dipancang never there. Landmark that dominates this area is Sutro Tower, a radio and television transmission towers of red and white.

A small earthquake occurred on a regular basis because of the San Andreas Fault and Hayward Fault. San Andreas Fault earthquake resulted in 1906 and 1989, the threat of major earthquakes plays a large role in the development of urban infrastructure. This city has repeatedly updating the building code, requires an update of the old buildings and a high technical standard for the construction of new buildings.

San Francisco waterfront has evolved through natural boundaries. Entire settlements such as the Marina and Hunters Point, as well as most of the Embarcadero, is above the landfills. Treasure Island was built from materials dredged from the bay and the results of drilling a tunnel through Yerba Buena Island during the construction of the Bay Bridge. Land like this tend to be unstable when an earthquake occurs, the melting of land resulting in widespread damage to property built upon it, as happened in the Marina district of the Loma Prieta earthquake of 1989.

Climate of San Francisco has the characteristics of summer-winter Mediterranean climate, on the California coast with cool, wet winters and dry summers and cold. Because it is surrounded by water on three sides, San Francisco weather is strongly influenced by the cold Pacific Ocean currents that regulate changes in temperature and produces cool climate all year round with little seasonal temperature variation.

Among the major cities in the U.S., San Francisco has a high temperature, maximum, and minimum daily requirement on the coldest June, July and August. During the summer, hot air rises in the deepest valley of California to form an interesting area of ​​low pressure Antisiklon wind from the North Pacific through the Golden Gate and form the cold winds and fog are typical for this city. During late summer and early autumn is the hottest time of the year.

Because the sharp topography and maritime influences, San Francisco has a series of different micro-climates. High hills in the geographic center of town is the cause of 20% variation in annual rainfall occurred in some areas of the city. The hills are also directly protect settlements east of the foggy weather and sometimes very cold and windy weather experienced in the Sunset District; for residents who settled on the east side of town, San Francisco is more sunny, with an average of 260 sunny days and 105 cloudy days each year .

The average temperature above 75 ° F (24 ° C) occurred only 28 days each May to October dry tahun.Periode was cool and warm, with the highest average temperature of 64-71 ° F (18-22 ° C) and low as 51-56 ° F (11-13 ° C). Periods of rain November to April is rather cool with the highest temperature 58-64 ° F (14-18 ° C) and the lowest temperature 46-51 ° F (8-11 ° C). On average, there are 67 rainy days per year, and annual rainfall average is 204 inches (5,181.60 mm). Snow very rarely appears, with 10 this phenomenon occurred since 1852 and the last occurred in 1976.

The highest temperature recorded in the official National Weather Service office is 103 ° F (39 ° C) on July 17, 1988 and June 14, 2000. The lowest temperature recorded was 27 ° F (-3 ° C) on December 11, 1932.