San Francisco is a major city in California, the centerpiece of the Bay Area, well-known for its liberal community, hilly terrain, Victorian architecture, scenic beauty, summer fog, and extreme ethnic and cultural diversity. These are only a few of the aspects of the city that make San Francisco one of the most visited cities in the world. San Francisco is located on a small seven-by-seven mile (11x11km) square of land at the tip of a peninsula between San Francisco Bay and the Pacific coast. It has a population of almost 800,000, but is the center of a metropolitan area of millions. San Francisco is just one of the cities which makes-up the entire San Francisco Bay Area. San Francisco's neighbors, cities and towns to the east of the Bay Bridge, north of the Golden Gate Bridge, and south of it are all in separate counties, each with their own city government and local public transportation systems. San Francisco has a mild climate, with wet, mild winters and dry summers. In most months, you can expect the temperature be in the 60s or 70s degrees Fahrenheit (between 15 and 25 degrees Celsius). Be prepared for cool humid weather, even in the summer (except September), when persistent fog often envelops the city. San Francisco's sharp topography has created a series of microclimates. For instance, there is more fog on the western side of the city, closer to the ocean. There can also be large variances in rainfall between different parts of the city thanks to the tall hills in the center of the peninsula (generally with more rain taking place on the western side, while the eastern side experiences more sunlight). http://wikitravel.org/en/San_francisco