Orinda is a city in Contra Costa County, California, United States. The population was 17,643 at the 2010 census, and was estimated in 2012 to have increased to 18,342. Orinda was ranked the second most friendly town in America by Forbes. The town is located just east of the city of Berkeley and is home to many affluent suburban professionals who commute to downtown Oakland, San Francisco, and Walnut Creek. Its location provides for a more rustic landscape, and Orinda’s many parks and trails make it a destination for many Bay Area hikers and naturalists.
Present-day Orinda was located within four Mexican land grants: Rancho Laguna de los Palos Colorados, Rancho Acalanes, Rancho El Sobrante and Rancho Boca de la Cañada del Pinole. The area was originally rural, mainly known for ranching and summer cabins. In the late 19th century, the land was named by Alice Marsh Cameron, probably in honor of the poet Katherine Philips, who was also known as the “Matchless Orinda”.
In the 1880s, the United States Surveyor General for California, Theodore Wagner, built an estate which he named Orinda Park. The Orinda Park post office opened in 1888. The post office’s name was changed to Orinda in 1895. Orinda was also the site of Bryant Station, a stop on the failed California and Nevada Railroad around the turn of the 20th century. In later times, the area around Bryant Station was known as Orinda Crossroads.
Orinda’s popularity as a year-round residence grew after the 1937 completion of the Caldecott Tunnel, which provided easier access to the west. Bisected by California State Route 24 and framed by its rolling oak-covered hills, the city of Orinda was incorporated on July 1, 1985. Its first mayor was Richard G. Heggie. The city has a station on the Pittsburg/Bay Point Line of the Bay Area Rapid Transit.
According to the United States Census Bureau, the city has a total area of 12.7 square miles (33 km2), of which, 12.7 square miles (33 km2) of it is land and 0.015 square miles (0.039 km2) of it (0.12%) is water.
The area is characterized by a warm-summer Mediterranean climate (Köppen climate classification Csb) with cool, rainy winters and warm, dry summers. It is located in the Chaparral biome. Because Orinda is located in a hilly area, microclimates often dominate temperature differences in short distances. The Oakland hills often block the cool foggy conditions that can be seen in Oakland and the innerbay. In the summer, fog can spill over the Oakland hills cooling off the area. Heatwaves from the inland areas can be felt much more in Orinda than in Oakland and the innerbay during the summer. In the winter, Orinda often sees more precipitation than surrounding areas because of its higher elevation. Snowfall is rare but not unheard of. A dusting of snow may occur any given year because of the elevation. During stable conditions in the winter, mornings can be rather cold and frosty in downtown and lower lying areas while the higher hills surrounding the area may be several degrees warmer.