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.
Monthly Date Sets for a likely arribada in Costa Rica - 2025
September 2025
New Moon: 21st
Be in the Ostional area: Sept, 18th – 25th
October 2025
New Moon: 21st
Be in the Ostional area: Oct, 18th – 25th
November 2025
New Moon: 20th
Be in the Ostional area: Nov, 17th – 24th
December 2025
New Moon: 19th
Be in the Ostional area: Dec, 16th – 23rd

Seeing an Arribada in Costa Rica - 2026 Season
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: 18th
Be in the Ostional area: Jan, 15th – 22nd
February 2026
New Moon: 17th
Be in the Ostional area: Feb 14th – 21st
March 2026
New Moon: 18th
Be in the Ostional area: March 15th – 22nd
April 2026
New Moon: 17th
Be in the Ostional area: April 14th – 21st
May 2026
New Moon: 16th
Be in the Ostional area: May 13th – 20th
June 2026
New Moon: 14th
Be in the Ostional area: June 11th – 18th
July 2026
New Moon: 14th
Be in the Ostional area: July 11th – 18th
August 2026
New Moon: 12th
Be in the Ostional area: Aug 9th – 16th
September 2026
New Moon: 10th
Be in the Ostional area: Sept, 7th – 14th
October 2026
New Moon: 10th
Be in the Ostional area: Oct 7th – 14th
November 2026
New Moon: 9th
Be in the Ostional area: Nov, 6th – 13th
December 2026
New Moon: 8th
Be in the Ostional area: Dec 5th – 12th
* 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.