California

California, United States ©

California Sea and Water Temperature

This page provides detailed information about the water temperature in California, United States. All cities and resorts on the coast, also in lakes and along the rivers. The range of sea temperatures for today. We find every spot where you can swim and tell you what the water temperature is there today and throughout the year.

Water Temperature in California: General Trends and Swimming Opportunities

California, with its extensive coastline along the Pacific Ocean, offers a wide variety of water temperatures that can differ significantly depending on the region. Along the southern coast, from San Diego to Los Angeles, the ocean water tends to be warmer, especially in the summer months, with temperatures ranging between 60°F and 70°F (16°C to 21°C). These warmer waters make for more comfortable beach activities, like swimming and surfing. In contrast, the northern coast of California, including areas like San Francisco and the rugged coastline of Mendocino, tends to have colder waters year-round. Here, water temperatures can range from 50°F to 60°F (10°C to 16°C), making it more difficult for casual swimming, although surfers still enjoy these areas due to the region’s world-class waves. Coastal water temperatures can also vary with ocean currents; for example, upwelling currents along the northern coast can cause water to cool down significantly.

California's rivers, which flow from the Sierra Nevada and other mountain ranges, also experience considerable variations in water temperatures. In the spring and early summer, when snowmelt fills the rivers, the temperatures can be quite cold, ranging from 40°F to 55°F (4°C to 13°C), even in popular rivers like the American River or Russian River. These temperatures are suitable for activities like kayaking and fishing but make swimming less appealing for most people. As summer progresses, especially in the lower elevation areas, river temperatures may rise slightly, reaching up to 70°F (21°C) in some sections, especially in reservoirs and slower-moving waters. However, the mountain streams and high-altitude rivers remain cold year-round, particularly in areas like the Kern River or the Merced River in Yosemite, where temperatures can stay well below 60°F (16°C).

Inland lakes throughout California, particularly those in the Sierra Nevada and other mountainous areas, also offer a variety of water temperatures. Large lakes like Clear Lake, Shasta Lake, and Big Bear Lake have warmer waters during the summer, often reaching temperatures between 70°F and 80°F (21°C to 27°C), making them ideal for swimming, boating, and water sports. These lakes provide a refreshing escape from the heat during the summer months. However, in the fall and winter, these lakes cool down significantly, with temperatures often dropping to around 40°F to 50°F (4°C to 10°C), which can make water activities less enjoyable. Smaller, higher-altitude lakes, such as those found in the Sierra Nevada or the Cascades, remain much colder, with water temperatures rarely reaching above 60°F (16°C) even in summer, making them better suited for fishing or scenic enjoyment than swimming.

Geographical Location of California

Frequently Asked Questions About California and its Water Temperatures