Fairfield, California is located in Solano County and has a Mediterranean climate with hot, dry summers and cool, wet winters. The city is situated near the Suisun Marsh, the largest estuary on the west coast of the United States, which provides an important habitat for a variety of fish and wildlife. The hydrology constituents of Fairfield include the Suisun Marsh watershed and the Putah Creek watershed, which supply water for agriculture and urban use. Outdoor recreation opportunities in Fairfield include hiking and biking in the nearby hills and wetlands, fishing and boating in the Suisun Marsh, and visiting local parks such as Rockville Hills Regional Park and Allan Witt Park.