Tamarindo in August is when turtle season starts to build. It is the month when many of our guests start planning a trip to Ostional, the countryside is at its greenest and the school-holiday crowds of July have gone home. The trade-off is simple: more afternoon rain in exchange for quieter days and some of the best wildlife of the year.
Short answer: August is a good month if turtles and green landscapes matter more to you than guaranteed sunshine. Mornings are often bright, afternoon showers and storms are more frequent than in July, and the main Ostional arribada season starts this month. Tamarindo is quiet after the school holidays, except on the long weekends of 2 and 15 August. Plan outdoor tours for the morning and keep one evening free for turtles.
Tamarindo weather in August: the rain returns
When the veranillo ends, the rainy-season rhythm comes back. A typical August day begins warm and clear, clouds build after midday and a shower or thunderstorm often arrives in the late afternoon or evening.
Some days pass with no rain at all. Others bring a heavy downpour that clears within an hour or two. Long, all-day rain is possible but less common than in September and October.
Rivers that were low in the dry season are flowing again, which is why waterfalls look their best from now on. Dirt roads in rural Guanacaste get muddier as the month goes on, worth knowing if you drive yourself. For the whole season, see our guide to the Tamarindo rainy season.
Costa Rica in August: holidays and crowds
With the mid-year school holidays over, Tamarindo settles into a calm green-season pace. Two national holidays can fill the town for a few days:
- 2 August, Virgin of Los Ángeles. The day of the patron saint of Costa Rica, when many pilgrims walk to the basilica in Cartago. When it makes a long weekend, some families head to the beach instead.
- 15 August, Mother’s Day. A public holiday celebrated with family meals and outings.
European summer travelers also visit in August. Overall, our shared tours have smaller groups than in July, and booking a day or two ahead is usually enough outside the holiday weekends.
Tamarindo in August: the start of arribada season
Ostional
Ostional, about 2 hours south of Tamarindo, is where thousands of olive ridley turtles can come ashore over a few days in an arribada. Smaller arribadas are possible from May, but August is when the main season starts; it continues to December, with the largest arribadas usually from September to November.
Each arribada lasts about six days and roughly one happens per month, but nobody can fix the date in advance. Our guide on how an Ostional arribada tour works explains the visit and the beach rules.
Nesting near Tamarindo
Solitary olive ridleys keep nesting on the beaches close to town, together with black turtles, and our night tour visits Playa Minas or Playa Jesús. Leatherbacks are not in season until October, and our sunset baby turtle release is available from November 12.
What our guides see on the estuary in August
The mangroves are at their lushest, and the water in the channels is higher and darker after the rains. Crocodiles are present as in every month, and on the boat our guides watch for them sliding off the banks as the tide comes in.
Late in the month, the first migratory shorebirds from North America can start to appear on the mudflats, a preview of the larger numbers that arrive later in the year. If birds are your interest, read our guide to birdwatching in Tamarindo. Sightings of birds or turtles are never guaranteed.
How rain and tides shape August tours
- Estuary boat and kayak tours leave with the high tide, so the time changes every day; we confirm it by WhatsApp after you book. A morning tide is the most comfortable choice in August.
- Afternoon tides often come with a light shower, and the tour continues. With lightning or unsafe conditions, we wait, offer another date or refund the deposit.
- The Ostional tour follows the arribada, not the tide. The departure is confirmed according to how the arribada develops, and part of the road is unpaved, so the drive takes longer after heavy rain.
- Full-day trips leave early, so most of the walking and swimming happens before the usual afternoon rain.
How to plan an Ostional arribada tour around your dates
- Send us your travel dates on WhatsApp before you arrive, so we can compare them with the expected arribada.
- Keep two evenings flexible; arribadas can start earlier or later than expected.
- Gather your group early: the tour needs a minimum of 4 people.
- Keep the night nesting tour near Tamarindo as a backup if the arribada does not match your stay.
What to pack for Guanacaste in August
- A light rain jacket or poncho for the afternoons.
- Quick-dry clothes and water shoes; cotton stays wet for hours in this humidity.
- Dark clothing and a camera you can use without flash for turtle tours.
- A change of clothes and a plastic bag for your phone on full-day trips.
- Insect repellent and sunblock; the sun is strong between showers.
Our guide on what to pack for Costa Rica tours has a full list by activity.
Things to do in Tamarindo in August: best tours
- Ostional arribada tour: $130 per person, minimum 4 people, children 3 and under free. Includes transportation from Tamarindo or Langosta, a bilingual guide, water and seasonal fruit. Deposit $20 per person.
- Tamarindo turtle tour: $60 per person, minimum 2 people, pickup in Tamarindo at 5:30 pm. If we do not see turtles, we reschedule for the next night or make it up to you with the estuary tour.
- Tamarindo mangrove tour by shared boat: $40 per person, 2 hours, with pickup from Tamarindo or Langosta.
- Sloth tour in Guanacaste and Llanos de Cortés waterfall: $185 per person, minimum 4 people, 6:30 am to about 6 pm, with transportation, entrance tickets and a Costa Rican lunch.
If your dates are flexible, compare with Tamarindo in July, drier but busier, and Tamarindo in September, when the arribadas peak.
Ready for turtle season? Reserve with Tamarindo Estuary Tours Mi Rey online with the deposit and pay the balance on the tour day, or write to us on WhatsApp to check the next expected arribada at Ostional.
Book these tours
Ostional Arribada Tour$130 per personSee tour and book →
Turtle Nesting Tour$60 per personSee tour and book →
Shared Boat Tour (Mangrove Safari)$40 per personSee tour and book →
Sloths and Llanos de Cortés Waterfall$185 per personSee tour and book →
Frequently asked questions
What is the weather like in Tamarindo in August?
August is a green-season month with warm, often sunny mornings and more afternoon showers and storms than July. Some days stay dry, and long all-day rain is less common than in September and October.
Can I do the Ostional arribada tour in August?
Yes, August is the start of the main arribada season, which runs to December with the peak from September to November. Arribadas happen roughly once a month for several days, so write to us on WhatsApp to ask when the next one is expected.
Are there public holidays in Costa Rica in August?
Yes. 2 August is the day of the Virgin of Los Ángeles and 15 August is Mother’s Day in Costa Rica. Both are public holidays and can bring national travelers to the beach on long weekends.
Is August a good month for a waterfall tour from Tamarindo?
Yes, the waterfalls usually carry more water than in the dry season, and our full-day trips leave early, before most afternoon rain. After heavy rain the guide decides on the day whether swimming is safe.
Do I need to book Tamarindo tours in advance in August?
For most tours, a day or two ahead is usually enough, except on holiday weekends. The Ostional tour needs a minimum of 4 people and depends on the arribada, so contact us as early as possible.
More Tamarindo guides
Tamarindo month by monthTamarindo in January: Weather, Crowds, Turtles and ToursTamarindo in January: dry, sunny and windy weather, peak season crowds, nesting turtles, how the tide sets the estuary tour and what to pack.
Tamarindo month by monthTamarindo in February: Dry Skies, Clear Nights and the Best ToursTamarindo in February: one of the driest months, fewer local crowds once schools reopen, turtles, monkeys in the bare dry forest and the tours that fit best.
Tamarindo month by monthTamarindo in March: Heat, Easter Week Crowds and the Best ToursTamarindo in March: hot and very dry, Easter week (Semana Santa) and spring break crowds, nesting iguanas and crocodiles, tides and the best tours to book.
Tamarindo month by monthTamarindo in April: The Hottest Month, Quieter Beaches and Smart ToursTamarindo in April: the hottest end of the dry season, quieter weeks after Easter, first rains, wildlife in the bare forest and tours timed to beat the heat.
Tamarindo month by monthTamarindo in May: First Rains, Green Hills and the Start of Turtle SeasonTamarindo in May: the first rains turn the dry forest green, low season brings quiet tours, olive ridley nesting increases and small Ostional arribadas begin.
Tamarindo month by monthTamarindo in June: Green Season, Fuller Waterfalls and Turtle NightsTamarindo in June: bright mornings and afternoon storms, a lush green estuary, waterfalls filling up, olive ridley nesting and quiet tours before July.