Weather in Costa Rica in August

August falls right in the middle of Costa Rica’s rainy season, which runs from May to November. You’ll get your fair share of heavy showers, especially in the afternoons. But this time of year is also known as the green season for a reason. The rain brings the countryside and rainforest to life. Here's our guide to the weather in Costa Rica in August.

Costa Rica in August at a glance

• Expect warm temperatures averaging around 81–87°F (27–31°C) across the country, with slightly cooler conditions in the Central Valley and highlands.
• It’s the rainy season, so expect some rain, especially in the afternoons.
• Tourism is moderate, with popular spots active but not overcrowded.
• This is the shoulder season, so accommodations tend to be more affordable.
   

What is the weather like in Costa Rica in August?

In August, Costa Rica is in its green season, which means you’ll get sunny mornings followed by afternoon showers. It’s a great time to explore the country’s natural beauty, especially in the early part of the day. The Pacific coast tends to get rain in the late afternoons, while the Caribbean side has more unpredictable weather. 

Rainfall in Costa Rica during August typically ranges from 8 to 12 inches (200-300mm). The South Pacific areas, like the Osa Peninsula, get the heaviest rain, while the Central Valley around San José sees about 8 inches (200mm) over 20 rainy days, though mornings are often clear. Since it’s low season, you’ll have fewer crowds, lush landscapes, and more affordable prices, and likely you’ll still get plenty of sunshine and wildlife activity.

Average daily temperatures in August

Temperatures in Costa Rica vary depending on where you are. During the day you can expect averages of 75-90°F (24-32°C), and at night it cools down to an average of 65-75°F (18-24°C). Ocean temperatures during this month are around 82-84°F (28-29°C), so it’s the perfect time for swimming, surfing, and snorkeling. There are about 12.5 hours of daylight, with sunrise around 5:15 a.m. and sunset around 5:45 p.m. For more tips, see our guide to how to plan a trip to Costa Rica.

Guanacaste & Northern Pacific

If you’re heading to Guanacaste and the Northern Pacific, August is a good time to visit. The veranillo effect makes this region the driest in the country during the month, with temperatures between 80-90°F (27-32°C). Rain is usually minimal, averaging just 5-8 inches (125-200mm) for the month, with short bursts in the afternoon. The mornings are sunny, which is perfect for enjoying the beaches, and the consistent offshore winds create great conditions for surfing, especially around Tamarindo and Nosara.

Central Pacific & Central Valley

In the Central Pacific and Central Valley, the weather is a bit more unpredictable. Mornings are usually sunny, with temperatures around 80-85°F (27-29°C) on the coast and 75-80°F (24-27°C) in the Central Valley. By the afternoon, clouds build up, and you’ll likely get some rain, particularly between 2 and 5 p.m. Places like Manuel Antonio, Jacó, and the Central Valley see around 10 inches (254mm) of rain in August. Despite the afternoon showers, Arenal Volcano and Monteverde Cloud Forest look especially vibrant at this time.

Caribbean Coast & Southern Zone

The Caribbean coast tends to be drier in August, with temperatures around 85°F (29°C) and about 8 inches (200mm) of rain. It’s actually a great time to visit areas like Puerto Viejo, Cahuita, and Tortuguero, which are usually much wetter in other months. On the flip side, the Southern Zone, including the Osa Peninsula and Corcovado National Park, experiences its heaviest rain in August, with up to 15 inches (380mm) of rainfall. Mornings are your best bet for activities since the afternoon showers can be heavy and long. But if you don’t mind getting wet, the rainforests and waterfalls in this area are breathtaking.
 

Is August a good time to visit Costa Rica?

Yes, August is a great month to visit Costa Rica. In the end, you’ll get lush landscapes, wildlife, and better value for your money.  The weather in August is typical of the green season, which means you’ll get sunny mornings followed by afternoon showers. This creates ideal conditions for outdoor adventures in the early part of the day and a relaxing afternoon once the rain hits. 

August also falls during the middle of sea turtle nesting season, especially at Tortuguero on the Caribbean coast, where you can witness green sea turtles coming ashore to lay their eggs. It’s an excellent time for wildlife viewing, too, with monkeys, sloths, and many bird species becoming more active and visible, particularly around water sources (see more about Costa Rica wildlife). Whitewater rafting is at its peak, and lush forests like Monteverde are particularly magical this month with thick mist.

What about the crowd & cost?

August is a good balance when it comes to crowds and costs. Since it’s the green season, you won’t have the overwhelming crowds of the high season, but there’s still enough activity around for things to feel lively. You can expect lower prices compared to the high season.

The first two weeks of August might feel a little busier because they line up with summer vacations in North America and Europe. If you’d rather have fewer people around and even better deals, September or October could be a good choice, though do keep in mind that the rain increases during these months, particularly on the Pacific side. See more in our guide to the best time to visit Costa Rica. 

Where to go in Costa Rica in August

The weather in Costa Rica in August means you'll want to expext regular afternoon rain, especially on the Pacific side, while the Caribbean coast tends to stay sunnier and drier.

Barra Honda National Park

Barra Honda is in the northwest, in Guanacaste Province, and it’s one of the few places in Costa Rica where you can explore limestone caves. August tends to be dry enough to get into the caves safely, especially Terciopelo, which is the most accessible. Inside, you’ll see all kinds of dramatic rock formations — it’s a cool change of pace if you’ve mostly been hiking or hanging out at the beach. The forest above ground is also worth walking through. You might see howler monkeys, coatis, and lots of birds. Since this area doesn’t get hit as hard with rain as other regions, it’s a decent bet for this time of year.

Gandoca-Manzanillo Wildlife Refuge

Located on the southern Caribbean coast, Gandoca-Manzanillo usually gets some of its best weather in August. It’s a quieter part of the country, with a mix of rainforest, beaches, coral reefs, mangroves, and wetlands all in one place. Wildlife is a big draw here — people often spot dolphins, manatees, crocodiles, and tropical birds (see our favorite Costa Rica rainforest tour). The local culture also feels different from the rest of Costa Rica, with strong Afro-Caribbean roots that come through in the food and music. 

Tamarindo

Tamarindo sits on the northern Pacific coast. It’s a well-known surf town that doesn’t completely shut down during the green season. Mornings are usually sunny, with rain more likely to roll in later in the day. That still leaves plenty of time to surf, swim, or explore nearby estuaries and mangrove forests. You’ll find a mix restaurants, stores, and beach bars all within easy reach. August usually brings fewer visitors, so it’s a good time to experience the town without the peak-season crowds — and the landscape turns a brighter green thanks to the rain.
 

Things to do in Costa Rica in August

August is part of the rainy season in Costa Rica, but that doesn’t mean you need to stay indoors. The rain tends to come in short bursts — often in the afternoon or at night — which leaves plenty of time for exploring. 

Green turtle nesting season

If you’re anywhere near Tortuguero in August, try to see the green turtles nesting. This is when they’re most active, hauling themselves up the beach at night to dig nests and lay eggs. It’s not something you stumble across on your own — you’ll need to go with a local guide on a night tour — but it’s absolutely worth it.

Tortuguero is only reachable by boat or small plane, so it feels pretty remote, and that’s part of the appeal. During the day, you can explore the park’s canals by boat and spot monkeys, sloths, caimans, and a surprising number of birds. For August, the weather here is actually pretty manageable compared to the wetter Pacific side. This is a great thing to do in Costa Rica with kids.

Mangrove kayaking

This time of year works well for kayaking through the mangroves because the extra rain raises the water level just enough to get into the narrower channels. If you’re in Tamarindo, the estuary is a nice place to paddle — calm water, plenty of birds, and the occasional crocodile. On the central Pacific coast, the mangroves around Damas Island are another good option. Most of these tours run in the morning to avoid the afternoon rain, and since they’re usually small groups in low-impact boats, it’s a quieter way to explore these ecosystems.

Frog watching night tours

August's increased humidity creates ideal conditions for amphibian activity, making this the premier month for frog watching night tours. Specialized guides lead small groups through forests and yards after dark, when dozens of frog species become active. The red-eyed tree frog, with its vivid coloration, is the most iconic, but you might also encounter glass frogs, poison dart frogs, and the massive cane toad. Many eco-lodges offer these tours on their properties. Beyond frogs, these nocturnal excursions often reveal tarantulas, sleeping birds, and even slow-moving sloths that might be missed during daylight hours.

Planning your trip to Costa Rica in August

Some Costa Rica travel tips to help you plan your trip:

What to pack

Pack for consistently wet conditions. A second pair of shoes is a good idea, since drying time can be slow. Moisture-wicking socks and quick-dry clothes help keep things comfortable. A basic laundry setup—a small detergent bottle, travel clothesline, and sink stopper—makes it easier to rewear essentials. Waterproof phone and camera cases are useful, and a small umbrella can double as sun protection. A power bank helps when solar charging is unreliable, especially in overcast areas.

For muddy hikes, gaiters are worth packing, and plastic or dry bags are great for separating wet and clean items.

Planning your itinerary

If you’re looking at Costa Rica for your vacation in August, starting with a good itinerary can make things easier. Here are some options to consider:

• Costa Rica itinerary 5 days: Check out San José’s cultural highlights, then head to La Fortuna for hiking trails and waterfalls. Explore Arenal Volcano’s hiking paths and hot springs, then finish in Monteverde’s cloud forest and hanging bridges, with a coffee farm tour back in San José.
• Costa Rica itinerary 7 days: Start in San José, then spend a few days in Manuel Antonio’s beaches and rainforests. After that, check out Monteverde’s cloud forest, zipper-lining, and hanging bridges. End in La Fortuna with Arenal Volcano’s trails, waterfalls, and hot springs.
• Costa Rica itinerary 10 days: Begin in San José, travel to Tortuguero’s canals, then explore La Fortuna’s rainforest and Arenal Volcano. Spend time in Manuel Antonio National Park with its beaches and diverse wildlife, and finish with some surfing and sunset views at Jaco Beach.
• Costa Rica itinerary 14 days: Begin in San José, then explore Tortuguero’s canals, Puerto Viejo’s Caribbean charm, and Cahuita’s coral reefs. Visit La Fortuna and Arenal Volcano, Monteverde’s cloud forests, and finish your trip in Manuel Antonio for beaches and wildlife.

When to book

This is the best time for the Caribbean coast—places like Puerto Viejo and Cahuita usually see more sun and calmer seas. If you’re planning a trip there, aim to book your place two to three months ahead, especially for beachfront spots. On the Pacific coast, things are quieter and often don’t require as much advance planning.

If you're interested in turtle nesting tours in Tortuguero, definitely book ahead—this is peak time, and tours fill up quickly. Over in Arenal and La Fortuna, you’ll likely get afternoon rain, but mornings are clearer, and the weather makes hot springs feel extra relaxing without big crowds.

Emergency weather information

August brings heavier, more consistent rain, and that means a few things: roads in the mountains—like near Arenal or Poás—can get sketchy fast. Landslides are common, so check route conditions before heading out and avoid driving when the rain’s really coming down. Rivers rise quickly too, so don’t be surprised if a rafting trip gets canceled last-minute. At the coast, erosion can create sudden drop-offs in the sand, and the Pacific side gets strong rip currents—only swim where there are lifeguards. You might see color-coded alerts from the National Emergency Commission (green, yellow, red).

 For more travel inspiration, see our guide to creating your own Costa Rica itinerary, with tips from local travel experts, or find extra ideas in our Costa Rica travel guide and tailored Costa Rica trips.