Richmond is a city located in West County Contra Costa, California, USA. Richmond is one of two cities, the other being San Rafael, California, which sits simultaneously at the shores of San Francisco Bay and San Pablo Bay. Its population is over 101,000 and has an area of 52 miles. Richmond is a city located in West County Contra Costa, California, USA. Richmond is one of two cities, the other being San Rafael, California, which sits simultaneously at the shores of San Francisco Bay and San Pablo Bay. Like most of the coastal East Bay, Richmond experiences a very mild Mediterranean climate during the year. The atmosphere is a little cooler than the San Francisco coastal areas.