“Hello, Baboo friends. I’m planning a trip to Costa Rica, and I’ve seen some spectacular videos of turtles nesting on its beaches. Do you know when is the best time of the year to see this incredible moment?”
Mark J.
Hi Mark. The “arribadas,” as they call them in Costa Rica, are a natural event impossible to predict 100%. However, there are more or less specific dates in parts of the country that are predictable. Costa Rica favors the visit of species such as turtles throughout the year. Five of the seven species of sea turtles in the world lay their eggs in Costa Rica.
The arrival of turtles to where they were born decades ago to lay their eggs is an authentic natural spectacle, whether in the Caribbean or the Pacific. This unique phenomenon can be observed throughout the year depending on the areas and the type of turtle you want to see.

Ostional National Wildlife Refuge – Kemp’s Ridley Turtle
Although olive ridley turtles nest solitarily all year round in this area of the Pacific (cataloged as one of the main nesting sites for olive ridley turtles in the world), Ostional beach is world-renowned for the massive and simultaneous nesting of thousands of olive ridley turtles. This phenomenon is known as “arribada” and occurs typically during every month of the year, but being a natural phenomenon, it is unpredictable.
On many occasions, they occur on dates close to the waning quarter. However, there are no exact dates of when it will happen.
The number of turtles depends on whether the phenomenon occurs in the dry season, approximately 12,000 turtles during 4 or 5 days (January to July) or in the rainy season (August to December), exceeding 100,000 individuals and with an average duration of 7 days. After laying their eggs in the sand, the females return to the sea in the early morning hours. On each outing, olive ridley turtles lay an average of 107 eggs.
Generally, the females come out at night. Still, sometimes, in large “arribadas,” they also come out during the day, observing the species an absolute delight for the eyes and an unforgettable experience, since, on occasions, the arrival of female turtles can be regarded with the birth of the tiny hatchlings trying to enter the sea.
Within the conservation efforts carried out in the Refuge is the vital work carried out by the members of the Association for Integral Development of Ostional (ADIO), who from the benefit they receive for the sustainable use of a small part of the olive ridley turtle eggs, they, in turn, assume a series of commitments and environmental responsibilities that help the work developed by the park rangers in the management of the Refuge:
- Keep the turtle nesting habitat clean and unobstructed.
- Develop surveillance and protection of the beach throughout the year.
- Care for and protect the hatchlings during mass hatching events of baby turtles and together with the accredited community guides.
- Collaborate in the organization of tourist visits and compliance with the regulations established to conserve this special place.
Tortuguero National Park – Leatherback Turtle
Tortuguero National Park is internationally recognized for hosting the fantastic spectacle of sea turtle nesting year. Four species nest here: green, leatherback, hawksbill, and loggerhead. All of them share the coastline, but on the nights of March and April, the leatherback turtle – the largest species of sea turtle – arrives in Tortuguero to nest on its beach.
The turtle digs a hole in the sand with her flippers, lays her eggs (82 to 112 eggs per nest), and covers it again with sand to protect them from predators. Finally, the female turtle returns to the sea while, on land, incubation lasts 50 to 75 days.

Visits to observe this unique natural phenomenon are always made with an authorized guide who informs visitors when is the best time to get close to see the turtles lay their eggs. If you are lucky, you will be able to observe the nesting and the hatching of the eggs and the tiny turtles as they struggle to reach the sea to not dehydrate and fall prey to any other animal.
Tortuguero National Park carries out a sea turtle observation program to adequately manage tourist visits and preserve the turtle nesting area. The program employs local people and allows for the sustainability of the park.
It is essential to mention that Tortuguero is also where the green turtle nests, but the nesting season is from July to October. Also, as a note, for turtle watching at night, you can only carry red light flashlights because it is believed that white light disorients the turtles.