Antioch, California is a suburban city with a warm Mediterranean climate, characterized by hot, dry summers and mild, wet winters. The city is located in Contra Costa County and is situated on the San Joaquin River, making it a hub for water-based outdoor activities such as boating, fishing, and kayaking. The river is also a source of hydrology constituents, which can include pollutants from urban runoff and agricultural activities. Antioch is home to several parks and nature preserves, including the Dow Wetlands Preserve and Black Diamond Mines Regional Preserve, which offer hiking and biking trails and opportunities for wildlife viewing.