Spearfishing During the San Diego Grunion Run: Seasonal Opportunity Window

The grunion run is one of San Diego’s most distinctive natural events—and it opens a unique window for spearfishermen willing to time it right. These small, silvery fish swarm our beaches during specific lunar phases to spawn, creating a concentrated feeding opportunity that rarely comes around. Understanding when, where, and how to fish during the run separates casual observers from prepared athletes.

What Is the Grunion Run?

Grunion (Leuresthes tenuis) are small jack smelt that spawn on Southern California beaches during high tides following specific full and new moons. They beach themselves to lay eggs in the sand, then return to the ocean. In San Diego, the run typically occurs from April through June and again from August through September—roughly the spring and late-summer lunar cycles.

The fish average 5–7 inches, making them a legitimate target for spearfishing despite their size. What matters is volume: during peak nights, thousands of grunion hit the sand, attracting predators and creating ideal conditions for divers and spearfishermen working the shallows.

Legal Framework and Timing

California Department of Fish and Wildlife (CDFW) regulations govern grunion fishing strictly. You cannot harvest grunion by hand or net during the spawning run itself—that’s off-limits. However, spearfishing grunion in the water before or after they beach is legal during open season.

The official grunion run forecast is published monthly by CDFW. Peak nights typically fall 3–4 days after the full or new moon, during the highest tides. Check the official forecast before heading out: timing is everything. A night off by one or two days can mean the difference between thousands of fish and a quiet beach.

Best San Diego Beaches for Grunion Spearfishing

Not all San Diego beaches are equal for grunion runs. Focus on these proven locations:

Silver Strand State Beach (between Imperial Beach and Coronado) is the most reliable and densest run in the region. Calm water, sandy bottom, and consistent spawning make it the top choice for spearfishermen.

Mission Beach and Pacific Beach see solid runs, especially the stretch between Ventura Point and Ocean Beach. The sandy bottom and proximity to deeper water create good hunting conditions.

La Jolla Shores has a more modest run but offers clearer water and easier access for snorkelers and free divers.

Sunset Cliffs Natural Park can see runs, but rocky terrain and surge make it less ideal for spearfishing compared to sandy beaches.

Avoid heavily congested areas like Coronado Central Beach during peak nights—crowds and hand-harvesters (where legal) create chaos and reduce your visibility and safety.

Seasonal Timing Strategy

Mark your calendar for the two primary windows:

Spring Run (April–June): Water temperatures climb from 60°F to the mid-60s. Visibility is typically 15–25 feet on calm nights. The longer daylight means you can scout beaches before dark and plan your entry.

Late Summer Run (August–September): Water temps peak at 68–70°F—ideal conditions. However, late-summer swells can make beaches choppy. Check conditions on Element before committing; a 2–3 foot swell can kill visibility and safety.

The 3–4 days following full or new moon during high tide are your sweet spot. Grunion typically run from about an hour before high tide through the peak, so plan accordingly.

Spearfishing Technique During the Run

Grunion are fast and skittish, but their sheer numbers work in your favor. Here’s the approach:

Shallow water hunting: Stay in 3–8 feet of water where grunion concentrate. Use a 5–7 foot spear gun with flopper tips—you don’t need power, just accuracy.

Timing: Hunt just before and during the run, not after fish have already spawned and retreated. The peak window is typically 2–3 hours centered on high tide.

Light discipline: A red or green headlamp attracts fewer fish than white light, but grunion are already focused on spawning—stealth matters less than positioning.

Patience over aggression: Grunion move in schools. Rather than chasing individual fish, position yourself in their path and wait for them to approach. A stationary spearfisher often has more success than one constantly swimming.

Safety first: Hunt with a buddy. Beaches during grunion runs attract crowds, and visibility underwater can degrade quickly with surge or sediment disturbance.

Preparation and Planning

Check Element for tide forecasts, water temperature, and swell conditions before each planned night. Bring a wetsuit (5mm for spring, 3mm for late summer), fins, and your spear gun. Verify the CDFW grunion forecast 2–3 days in advance—there’s no point showing up on the wrong night.

Scout your beach during daylight to identify entry points, rocky hazards, and good hunting zones. The difference between a productive night and a wasted one often comes down to knowing the bottom topography.

Seasonal Opportunity

The grunion run is a brief, predictable seasonal event that rewards preparation. Unlike year-round fishing, it concentrates fish, creates natural timing windows, and offers something genuinely different from standard spearfishing. In San Diego, it’s one of the few times when conditions align perfectly for both predator and prey.

Use Element to track tides, moon phases, and water conditions so you’re ready when the run comes. Plan ahead, respect CDFW regulations, and you’ll maximize your opportunity window.