Best Time to See an Arribada in Costa Rica – 2025/2026 Nesting Season Guide

So you want to see an Arribada in Costa Rica. As we are coming to the end of 2025 and peek Arribada season here in Costa Rica, we want to touch on the best nights to witness an arribada in these final months of 2025 and look forward to the 2026 Olive Ridley Sea Turtle nesting season.

What is an arribada?

If you are just learning about arribadas, or have no idea what one is, Arribada is the Spanish word for “arrival”, in this case, it refers to a mast nesting event of the Olive Ridley Sea Turtle. Here in Costa Rica we have many nesting beaches and several species of turtles that nest here. Arribadas are a little different, imagine hundreds, thousands, tens of thousands of turtles all coming to shore to nest at the same time! This happens over a few days, and it is truly a wonder of nature. This can be a life-changing event for many people who witness the phenomenon, it is humbling.

Where to see an Arribada?

To see an arribada you need to be in the right place at the right time. This only happens in a handful of places around the world, and here in Costa Rica, we have 2 beaches where they nest in large numbers. Ostional in the Ostional Wildlife refuge, and Playa Nancita, in Sant Rosa National park further north.

Ostional, Costa Rica - This is the more accessible area for seeing an arribada. Getting to see an arribada you need to be in the area for a few days. This is always going to be hit or miss, nature is going to cooperate, or not. You can stay in the area, or nearby in Nosara or Sámara. All 3 put you in position to see an arribada.

When to see an Arribada - Moon Cycles and Best Nights for an Arribada – Having an understanding of moon cycles is crucial. Turtles nest on the darkest nights of the month, this means you want to be in the area usually a few days before a new moon. The days leading up to the new moon and a few days after are the darkest of the month and most likely the time for nesting activity. In a nutshell, 3-4 days before the new moon on through to 3-4 days after the new moon, that will increase your odds. This chart is a great visual representation of moon cycles.

September 2025
New Moon: 21^st
Be in the Ostional area: Sept, 18^th – 25^th

October 2025
New Moon: 21^st
Be in the Ostional area: Oct, 18^th – 25^th

November 2025
New Moon: 20^th
Be in the Ostional area: Nov, 17^th – 24^th

December 2025
New Moon: 19^th
Be in the Ostional area: Dec, 16^th – 23^rd

Looking ahead into the 2026 Arribada season, we can determine what likely will be the best nights to be in the right area of Costa Rica and the right time of month. With that, let’s explore 2026.

January 2026
New Moon: 18^th
Be in the Ostional area: Jan, 15^th – 22^nd

February 2026
New Moon: 17^th
Be in the Ostional area: Feb 14^th – 21^st

March 2026
New Moon: 18^th
Be in the Ostional area: March 15^th – 22^nd

April 2026
New Moon: 17^th
Be in the Ostional area: April 14^th – 21^st

May 2026
New Moon: 16^th
Be in the Ostional area: May 13^th – 20^th

June 2026
New Moon: 14^th
Be in the Ostional area: June 11^th – 18^th

July 2026
New Moon: 14^th
Be in the Ostional area: July 11^th – 18^th

August 2026
New Moon: 12^th
Be in the Ostional area: Aug 9^th – 16^th

September 2026
New Moon: 10^th
Be in the Ostional area: Sept, 7^th – 14^th

October 2026
New Moon: 10^th
Be in the Ostional area: Oct 7^th – 14^th

November 2026
New Moon: 9^th
Be in the Ostional area: Nov, 6^th – 13^th

December 2026
New Moon: 8^th
Be in the Ostional area: Dec 5^th – 12^th

* Remember, there are no guarantees to see an arribada on these dates, sometimes they come early, sometimes they come late, and sometimes they do not come at all. They prefer to nest in the green/rainy season, and they prefer dark nights. 

We hope you found today's post on arribadas helpful! We do this post every year in hopes that more people become aware of the magic of nature, and the wonders she has to show us. If you are interested in seeing an arribada and are planning your vacation with us, please let your travel planner know. Contact us at info@crreferrals.com or you can start building your Costa Rica trip here.