How Upwelling Season Affects San Diego Water Temperature and Wetsuit Choice

San Diego’s water temperature isn’t a simple linear progression through the seasons. Instead, it follows a pattern shaped by coastal upwelling—a phenomenon that makes summer water colder than you’d expect and catches many visiting surfers off guard.

What Is Upwelling and Why It Matters

Upwelling occurs when sustained northwesterly winds push warm surface water away from the coast, allowing cold, nutrient-rich water from deeper in the ocean to rise and replace it. In San Diego, this process intensifies from April through October, with peak intensity typically occurring June through August.

The timing is counterintuitive. While inland San Diego bakes in summer heat, your local breaks experience their coldest water of the year. Windansea, Blacks Beach, and Mission Beach can drop to 57–60°F in July and August—colder than winter water in many other parts of California.

The San Diego Temperature Cycle

Winter (December–February): Water temperatures range from 57–60°F. Weak upwelling means warmer water persists relative to summer. Most San Diego surfers wear 4/3mm or 5/4mm wetsuits.

Spring (March–May): Water begins cooling as upwelling intensifies. Temperatures drop from 60°F to 58–59°F by May. A 3/2mm suit works for protected breaks, but thicker suits become necessary at exposed reefs like Sunset Cliffs and Ocean Beach.

Summer (June–August): Peak upwelling creates the coldest water of the year. Ocean Beach, Sunset Cliffs, and the Torrey Pines area can reach 56–58°F. La Jolla Cove and nearby kelp forests stay slightly warmer (59–61°F) due to shelter, but expect cold water throughout San Diego County.

Fall (September–October): Upwelling weakens as winds shift. Water temperatures gradually warm from 58°F to 62–64°F. By late October, water begins its slow climb toward winter patterns. A 3/2mm or 4/3mm suit becomes practical again.

Choosing Your Wetsuit for Upwelling Season

June–August (Peak Upwelling): Go thicker than you think. A 4/3mm or 5/4mm full suit is standard. If you’re sensitive to cold, a 6/5mm with booties and gloves makes sense, especially for dawn patrols at Blacks Beach or extended sessions at Windansea. Don’t underestimate the psychological drain of prolonged cold exposure—it dulls your focus and shortens your session quality.

April–May & September–October (Transitional Months): A 3/2mm works for sheltered breaks and midday sessions, but keep a 4/3mm in your car. Microbursts of colder water can arrive unexpectedly, and the difference between comfort and shivering is one suit thickness.

Spot-Specific Considerations:

• Blacks Beach & Torrey Pines: Most exposed to upwelling. Expect water 2–3°F colder than Mission Beach. Wear your thickest suit here.
• Ocean Beach & Sunset Cliffs: Highly exposed reefs that funnel cold upwelled water. Same logic applies.
• Mission Beach & Pacific Beach: Slightly warmer due to bay protection. Still cold in summer, but noticeably warmer than southern breaks by 1–2°F.
• La Jolla Cove: Kelp forests and cove geometry provide some thermal buffering. Water is typically 2–3°F warmer than Blacks Beach during peak upwelling.

Beyond Thickness: Material and Fit

Neoprene thickness is only half the equation. Modern wetsuits use premium neoprene blends (limestone-based, sealed, or graphite-lined) that retain heat better than entry-level suits. If you’re serious about summer sessions, invest in quality. A 4/3mm premium suit outperforms a 5/4mm budget suit.

Fit matters too. Loose suits allow water circulation that kills warmth. Get a snug fit without restricting movement. Chest zips and back zips have trade-offs—chest zips seal better but are harder to get on; back zips are easier to don but let in slightly more water.

Booties and gloves extend your session comfort significantly during peak upwelling. A 2mm bootie and 3mm glove add 15–20 minutes of usable time on cold mornings.

Plan Your Sessions Around Temperature

Check water temperature forecasts before paddling out. Element tracks real-time San Diego water temps across major breaks. A 56°F reading at Blacks Beach means you’re looking at genuine cold-water conditions—not a casual morning swim.

Early summer (June) tends to be slightly warmer than mid-summer (July–August) as upwelling ramps up. If you’re planning a trip to San Diego in summer, expect the coldest water of your year and pack accordingly.

Final Takeaway

Upwelling season defines San Diego summer surfing. It’s not a weakness in the forecast—it’s a feature. Cold water means clean, consistent swells, organized wind patterns, and fewer crowds. Respect the temperature, dress appropriately, and you’ll unlock some of the year’s best sessions.

Use Element to monitor water temperature and swell forecasts across San Diego’s best breaks, and dial in your wetsuit choice before you paddle out.