Spearfishing During El Niño Years in San Diego: Water Temperature and Species Shifts

El Niño years bring dramatic shifts to San Diego’s marine environment—and spearfishers who understand these changes gain a real edge. Water temperatures spike, thermoclines move, and species composition changes. What works in a neutral year might fail during El Niño. Here’s what you need to know to adapt your hunting strategy.

How El Niño Warms San Diego Waters

During El Niño events, warm equatorial Pacific water pushes northward, raising sea surface temperatures across Southern California by 2–4°F on average. For San Diego, this typically means water temps climbing from the normal 58–62°F winter range to 64–68°F or higher.

This warming isn’t uniform. The warmest anomalies often occur offshore, while nearshore reefs near Ocean Beach and Mission Bay stay slightly cooler. The key thermocline—the sharp temperature boundary fish use for navigation—shifts deeper, usually from 40–60 feet down to 70–90 feet. This vertical shift directly impacts where you’ll find your target species.

Species You’ll See More (and Less) Of

Yellowtail and Dorado

El Niño years are boom years for yellowtail (amberjack) and dorado off San Diego. Warmer water extends their range northward and keeps them present longer into fall. During strong El Niño events (2015–2016, 2023–2024), yellowtail appeared in numbers around La Jolla Shores and the kelp beds off Point Loma starting in late summer. These fish stay deeper during El Niño—expect them below 80 feet rather than the typical 40–60-foot range.

Dorado (mahi-mahi) show up earlier and stay later. They’re rarely seen in San Diego outside El Niño years, but during warm cycles, they’re viable targets off the continental shelf and around floating kelp paddies.

Calico Bass Retreat

Warmer water pushes calico bass (kelp bass) deeper and farther from nearshore reefs. Your productive 30–50-foot hunting grounds near the Coronado Islands and Crystal Pier become less reliable. Instead, focus on deeper kelp forest edges and rocky outcrops at 60–80 feet.

Sheephead and White Seabass Hold Steady

These species are less sensitive to temperature swings. Sheephead remain in their usual spots around rocky reefs throughout El Niño years, though they may move slightly deeper. White seabass stay viable in deeper channels like the San Diego Trough, though overall densities can fluctuate.

Practical Adjustments for El Niño Spearfishing

Go Deeper

The most immediate shift: fish move deeper. Your standard 40-foot dives become less productive. Plan dives to 70–100 feet, especially around Point Loma, the Coronado Islands, and offshore reefs. This requires deeper air reserves and better buoyancy control.

Hunt Later in the Season

El Niño extends the spearfishing season. Warm water keeps fish active longer into November and December. While your typical September peak may flatten, October through early December often delivers consistent action. Plan your bigger hunting trips for fall rather than early summer.

Focus on Offshore Reefs

Nearshore spots like Ocean Beach Pier and Mission Bay see reduced productivity during El Niño warmth. Offshore reefs—Coronado Islands, the Wreck, and deeper structures near Point Loma—become more reliable. These spots stay cooler and hold denser concentrations of deep-adapted species.

Scout Kelp Conditions

Warmer water weakens kelp growth. Expect thinner, less dense kelp forests during El Niño years. This actually improves visibility and maneuverability in some cases, but means fewer fish using kelp as cover. Shift focus to rocky reefs and hard bottom rather than pure kelp hunting.

Watch for Bioluminescence

Warmer water often triggers dinoflagellate blooms. You’ll see more bioluminescence on night dives and low-light conditions. Plan dives for midday when visibility is best, rather than dawn or dusk hunting.

Timing Your Hunts

Strong El Niño events typically peak November through February. In San Diego, this means:

• Late summer (August–September): Yellowtail appear earlier; hunt deeper reefs.
• Fall (October–November): Peak season for warm-water species; offshore reefs are most productive.
• Winter (December–February): Dorado and yellowtail remain viable; water temps stabilize higher than normal.

Neutral and La Niña years see cooler water, shallower thermoclines, and better nearshore hunting. Use the Element app’s seasonal patterns and water temperature data to track these shifts in real time.

The Adaptive Hunter Wins

El Niño isn’t a barrier—it’s a pattern shift. Successful spearfishers in San Diego adjust depth, location, and timing rather than abandoning their hunts. Scout deeper reefs, extend your season into fall, and focus on warm-water species. The fish are still there; you just need to follow them deeper.

Track water temperature and seasonal anomalies with the Element app to stay ahead of El Niño shifts and plan your best hunts.