Most Los Angeles beaches empty out by midnight. But on a handful of nights each year, the sand fills again with people clutching flashlights and waiting in the dark for thousands of small silvery fish to wash ashore, spawn, and slip back into the surf. It’s not a special effect — it’s a grunion run, and it’s one of the most genuinely unusual things you can do with kids in Southern California.
What makes this phenomenon so strange is that these fish don’t just swim close to shore. They leave the water entirely. Female grunion wriggle tail-first into wet sand, deposit their eggs, and return with the next wave — all in about thirty seconds. Males circle around and fertilize the nest before retreating. The whole thing happens on a predictable schedule tied to the full and new moons, which means you can plan for it.
What a Grunion Run Actually Looks Like
California grunion are small, sardine-like fish that run five to six inches long, with some reaching seven inches. They’re found only along the coast of Southern California and northern Baja California. On spawning nights, they ride the highest tides onto gently sloping sandy beaches. The females arch their bodies and use their tails to excavate a nest about four inches deep in the sand, then deposit between 1,600 and 3,600 eggs in a single spawn. The eggs incubate in the sand for about ten days, kept moist by residual water, until the next series of high tides inundates them and the hatchlings wash out to sea.
On good nights, Cabrillo Beach can be blanketed with silvery grunion. The number of fish varies widely — from a handful to a thousand or more per run. The heaviest part of the run usually occurs at least an hour after it starts, and the best runs tend to happen on the second and third nights of the four-night spawning period.
On good nights, Cabrillo Beach can be blanketed with silvery grunion.
When to Go: Reading the 2026 Schedule
The California Department of Fish and Wildlife publishes an expected grunion run schedule a year in advance, based on tide and moon cycles. The runs occur from March through August, with peak spawning from late March to early June. By August, runs tend to be more sporadic.
The schedule gives a two-hour window for each predicted run — the second hour is usually better. Times are listed for Cabrillo Beach near the Los Angeles Harbor entrance. If you’re watching in San Diego, expect runs about five minutes earlier; in Santa Barbara, about twenty-five minutes later.
For 2026, open-season runs when you can both observe and catch grunion by hand include dates in March, July, and August. March dates include the 3rd through 6th, 18th through 21st, with windows starting between 9:35 p.m. and 11:30 p.m. July runs start the 1st, 2nd, 14th through 17th, and 29th through 31st, with windows from 9:45 p.m. to as late as 2:10 a.m. August runs span the 12th through 15th and 28th through 30th.
Closed-season runs — observation only, no touching — occur in April, May, and June. April 2026 runs include the 1st through 4th and 17th through 20th. May runs cover the 1st through 4th, 16th through 19th, and 31st. June runs span the 1st through 3rd, 14th through 17th, and 29th through 30th.
The schedule is released annually by the California Department of Fish and Wildlife, and you should check the seasonal grunion run schedule for updates before heading out.
Cabrillo Beach and the Aquarium Program: The Easiest Way to See a Run
For Los Angeles County residents, Cabrillo Beach in San Pedro is the most reliable place to catch a grunion run. The beach sits near the entrance to Los Angeles Harbor, and it’s where the CDFW bases its schedule predictions.
The Cabrillo Marine Aquarium has been hosting public grunion programs since 1964. On program nights, doors open at 8 p.m. The evening starts at 9 p.m. with a staff lecture and a screening of “Fish, Moon and Tides: The Grunion Story,” a film produced in 1964 that explains the biology and timing of the runs. After the film, the group walks to the beach.
Aquarium educators set up lab stations along the sand where you can observe the fish up close. They also distribute jars of grunion eggs collected from a previous run — the eggs hatch when agitated by ocean water, which gives kids a front-row seat to the life cycle. Admission is $5 for adults and $1 for children.
The program removes most of the guesswork. You don’t need to wonder whether the fish will show up, where to stand, or whether you’re breaking any rules. The aquarium handles the logistics. They also host a once-per-season Grunion Fish-tival with additional activities, plus “Meet the Grunion” events on select nights in April, May, and June during the closed season.
Rules of the Run: What You Can and Can’t Do
The rules change depending on the month. During the closed season — April, May, and June — you may observe grunion runs only. No contact with the fish is permitted. This protects the peak spawning period.
During the open season — March, July, and August — you may catch grunion by hand only. No holes may be dug in the beach to entrap them. Anyone sixteen years or older needs a valid California sport fishing license with an ocean enhancement stamp to catch or even touch the fish. Kids under sixteen can catch grunion without a license. The daily bag and possession limit is thirty fish.
If you’re just watching, no license is needed. But any interaction with the fish — even if you’re not keeping them — requires a license for anyone sixteen and up.
The California Department of Fish and Wildlife does not recommend specific beaches for grunion runs due to changing safety conditions and local curfews. The best way to find beaches with recent runs is to call state and county beach lifeguards, who can often tell you if spawning has taken place nearby.
Who This Works For
Grunion runs suit families with kids who can manage a late night. The windows start between 9 p.m. and midnight, and the best action often comes in the second hour. That means you’re on the beach until 11 p.m., 1 a.m., or later. For younger children, the March and early July runs with earlier start times are the most manageable.
The experience rewards patience. You wait on a dark beach, speaking quietly, until the fish arrive. The aquarium program helps by filling the wait time with the lecture and film. Kids who enjoy nature, marine biology, or just the thrill of seeing something strange will be captivated. Kids who need constant stimulation or who crash early will struggle.
This is not an activity for anyone who wants a guaranteed show. Some nights deliver a beach covered in silver. Other nights deliver a handful of fish. The aquarium program improves your odds because the staff knows where and when to look.
What Goes Wrong and How to Avoid It
Grunion are sensitive to vibration and bright lights. If spectators arrive noisily or use flashlights before the staff gives permission, the fish may not approach the beach at all. The aquarium program enforces quiet arrival and dark conditions for exactly this reason.
Leaving too early is the most common mistake. People watch the first wave of fish, think that’s the whole show, and miss the main event. The heaviest part of the run usually comes at least an hour after it starts. Plan to stay for the full two-hour window.
Weather and surf conditions can cancel or reduce a run. High surf, coastal flooding, and rip currents — which can occur when tropical influences reach Southern California — may make beaches unsafe. Always check conditions with the local lifeguard before heading out.
Some beaches have local curfews. Cabrillo Beach is the safest bet because the aquarium program has permission for late-night access. If you go to another beach independently, confirm that late-night access is allowed.
Making a Night of It in San Pedro
San Pedro sits at the southern end of Los Angeles, about thirty minutes from downtown. If you’re coming from elsewhere in the city, plan the drive as part of the evening. The aquarium is located at 3720 Steven M. White Drive, right on the water.
Before the program, grab dinner in San Pedro’s waterfront dining area or pack a picnic for the beach. The nearby Long Beach cruise terminals with their distinctive geodesic dome are a short drive away and worth a look during daylight hours if you’re making a full day of it.
For families planning a broader Los Angeles trip, the Los Angeles destination guide covers the full range of things to do, from daytime museums to late-night beach adventures like this one.
What to Bring
Dress for the beach at night — even in summer, the coastal breeze can be cool. Wear dark clothing to avoid startling the fish. Bring a flashlight, but use it only when staff gives the go-ahead. A blanket or low chair helps during the wait. If you’re planning to catch grunion during open season, bring a bucket and your fishing license if you’re sixteen or older.
Leave beach toys, loud gear, and bright phone screens behind. The quieter and darker you are, the better your chances of seeing a full run.
Sources
California Grunion Facts and Expected Runs. California Department of Fish and Wildlife, 2026.
Grunion Runs: That SoCal Thing When Thousands of Fish Crawl Up the Beach. Mommy Poppins, 2026.
Cabrillo Marine Aquarium Grunion Program Schedule and Fees. Cabrillo Marine Aquarium, 2026.
Grunion Run Schedule. California Beaches, 2026.
Grunion.org Research Website. Dr. Karen Martin, Pepperdine University.
