San Ramon (Spanish: San Ramón; meaning Saint Raymond”) is a city in Contra Costa County, California, United States. It is a suburban city of the San Francisco Bay Area, and lies in the San Ramon Valley. San Ramon’s population was 72,148 as of the 2010 U.S. Census, with an estimated population of 74,378 in 2012, making it 4th largest city in Contra Costa County, behind Richmond, Concord and Antioch.

San Ramon is home to the headquarters of the Chevron Corporation, 24-Hour Fitness, the West Coast headquarters of AT&T Inc., The Global Software Center of GE, as well as the San Ramon Medical Center. Major annual events include the Art and Wind Festival on Memorial Day weekend, the Fourth of July Picnic and Fireworks Show, and the Primo’s Run for Education in October. The city is also home to California High School, founded in 1973 and ranked 250th best high school in the United States by Newsweek.

San Ramon is located at 37°46′48″N 121°58′41″W. It is adjacent to Danville, California, to the north and Dublin, California, to the south. Unincorporated county lands border San Ramon to the east and west. It is located around 500 feet (150 m) above sea level. Mount Diablo flanks the city to the northeast and is prominently visible from almost all parts of the city. The Las Trampas Regional Wilderness borders San Ramon’s extreme northwest, at the northern end of Bollinger Canyon. The smaller Bishop Ranch Regional Preserve straddles San Ramon’s western border, located approximately between Interstate 680 and the Alameda County line.

The topography of San Ramon is varied, featuring a mix of the rolling hills of the Diablo Range and the flatter basin of the San Ramon Valley. The city is predominantly urban and residential; however much of the land around the city’s perimeter regions remains undeveloped, and is covered by grasslands and oak tree orchards. During the drier months the grasses are golden; with the precipitation of winter and spring, the grasses turn green.

San Ramon’s weather typifies the Mediterranean climate; temperate, seasonal, and moderate. Summers are warm and dry, while winters are mild and damp. Its weather is similar to the adjacent cities of Danville, Dublin and Pleasanton. Fog is a relatively infrequent but normal occurrence in the western reaches of the city, at the eastern mouth of Crow Canyon, through which marine weather patterns funnel in from the San Francisco Bay via Castro Valley. It usually burns off by mid-to-late morning.

The city of San Ramon is planning a new 40-acre (160,000 m2) downtown that will include a public plaza, hotel, independent cinema and a mix of residential units plus a new city hall, library, transit center and office space, to be developed by Sunset Development Company, the original developers of Bishop Ranch. As of May 2010, the start of construction of the new City Center was postponed due to the economic decline; however the project was fully approved and ready to move forward when economic conditions improve.