How Upwelling Affects Water Temperature and Visibility Off Point Loma

Point Loma’s water conditions are governed by a seasonal cycle most San Diego freedivers don’t fully understand: upwelling. This oceanographic phenomenon dramatically shifts temperature and visibility throughout the year, making the difference between a comfortable dive and a challenging one. Understanding how upwelling works—and when it peaks—is essential for planning your freediving sessions.

What Is Upwelling?

Upwelling occurs when deep, cold ocean water rises toward the surface, replacing warmer water that has moved offshore. Along the California coast, this happens predictably during spring and summer (roughly March through September) when northwesterly winds push surface water away from shore. As that water moves seaward, cold water from depths of 100–300 feet wells up to fill the void.

Point Loma sits directly in the path of this upwelling zone. The point’s geography—jutting into the Pacific with deep water immediately offshore—makes it one of San Diego’s most reliable upwelling hotspots. When conditions align, water temperatures can drop 10–15°F in just weeks.

Temperature Swings and Seasonal Patterns

In winter (December–February), Point Loma’s water typically ranges from 57–60°F. It’s cold, but relatively stable. Spring arrives, northwesterly winds increase, and by April, upwelling intensifies. By June and July, water temperatures can plummet to 52–55°F offshore of Point Loma’s tip. This is peak upwelling season.

For freedivers, this means thermal protection is non-negotiable. A 3mm wetsuit becomes inadequate; most experienced Point Loma freedivers switch to 5mm or 7mm suits from May through August. Gloves and booties become standard, not optional.

By late September, upwelling weakens as wind patterns shift. October through November see a gradual warming trend, with temperatures climbing back to 58–62°F. This brief window offers the most comfortable water conditions of the year for freediving, which explains why many local divers schedule their deepest dives in fall.

Visibility: The Upwelling Trade-Off

Upwelling brings nutrient-rich water to the surface, and those nutrients fuel phytoplankton blooms. More plankton means less light penetration and reduced visibility—sometimes dramatically.

During peak upwelling (June–August), visibility off Point Loma can drop to 15–25 feet. The water takes on a greenish or brownish tint. For spearfishing, this is challenging. For training and depth work, it’s manageable but requires adjusted techniques.

However, upwelling doesn’t always reduce visibility. In early spring (March–April), before phytoplankton populations fully bloom, you might experience 40–50 feet of visibility with cool water still developing. These brief windows are gold for Point Loma freedivers. Check the Element app for real-time visibility reports to catch these optimal conditions.

Conversely, winter often brings the best visibility (50–70 feet) but the coldest water. It’s a classic trade-off: comfort or clarity. Most freedivers choose comfort in summer and accept reduced visibility, then switch to winter dives when they want maximum sight distance.

Why This Matters for Your Dives

Upwelling directly impacts how you plan your sessions:

Summer dives (June–August): Expect cold water, reduced visibility, and the need for heavy thermal protection. These conditions are ideal for training—you learn to manage thick wetsuits and adapt to limited visual cues. Stick to shallower depths and familiar sites like the kelp forests near Sunset Cliffs where structure helps with navigation.

Fall dives (September–November): This is peak season. Warming water, residual visibility, and fewer crowds make October the best month for serious freediving off Point Loma.

Winter dives (December–February): Best visibility, coldest water. Plan deeper dives when you want to maximize sight distance, but budget for heavier thermal gear.

Spring transition (March–May): Unpredictable. Upwelling is ramping up, visibility fluctuates, and water temps are dropping fast. Use the Element app to monitor conditions daily rather than planning weeks in advance.

Practical Application

The most successful Point Loma freedivers don’t fight upwelling—they adapt to it. They keep multiple wetsuits in rotation. They learn to read water color and temperature trends. They use tools like Element to track real-time conditions rather than relying on memory or outdated reports.

If you’re planning a dive trip to Point Loma, check the upwelling forecast and water temperature data before committing. A 5°F difference in water temperature changes everything about how you’ll perform and feel in the water. Upwelling is predictable; working with it, not against it, is what separates consistent freedivers from frustrated ones.

Use the Element app to track Point Loma’s water temperature, visibility, and upwelling intensity in real time—so you can dive when conditions align with your goals.