sunset over Corcovado National Park


Located in the southern Pacific region of Costa Rica, the Osa Peninsula experiences a tropical climate with warm temperatures and high humidity. The average temperature ranges between 75°F to 85°F (24°C to 29°C), and there is little variation throughout the year. Visitors should note that the high humidity levels can make the air feel warm and sticky, especially during the green season from May to November.

Rainfall is significant throughout the year on the Osa Peninsula, with the heaviest rainfall occurring during the rainiest months of October and November. Daily rain showers are common during this time. Windy conditions can also occur, especially near the coast, due to the trade winds bringing gusts of wind to the region.

However, despite the frequent rain, the Osa Peninsula also has sunny days, and visitors can expect to experience plenty of warm temperatures and sunshine throughout the year. It is recommended to come prepared for the tropical climate with lightweight and breathable clothing, as well as sunscreen and insect repellent.

Osa Peninsula Weather – the sunrise is around 5:15am and the sunsets are at about 5:45pm consistently throughout the year.

Why? We are only about 1,000 kms from the equator.

The lunar cycle will also effect a lot of natural things on the Osa Peninsula from tides to animal habits. You will definitely the efects of the full moon on the Osa Peninsula. 

OsaTourism Osa Peninsula Tourist Information





The weather on the Osa Peninsula Costa Rica has 3 relatively distinct seasons; the Dry Season (High Season); the Green Season; and the Wet Season. Each has its colourful characteristics. 

The dry season is from December – April. Temperatures vary depending on elevation. EcoLodges in the higher elevation have cooler nights. This temperature variation can be felt in the rivers that flow from the mountain tops…as the water cascades down to sea level it warms. The waterfalls on the Osa Peninsula, which there are many, are cooler than the surface of the Pacific Ocean. You can see this effect on the surface of the Golfo Dulce…as rivers of fresh cooler water float on the surface of the warmer seawater, making smooth and shiny trails on the surface of the gulf.

sa Peninsula rivers

kms from the Equator

Sunsets over Osa


The green season is from May – November. The rains bring cooler temperatures with them. But May to September is beautiful here with the rivers flowing, waterfalls pumping and things beginning to grow. The storms are incredible to experience. The thunder can be intense, yet is another unique Osa characteristic. The tunes of nature here are magical. And the wildlife reacts to the changes. 

We feel it is important for everyone to know that October and November can be intense. Normally, the most rain we get is in late October and early November. A lot of the ecolodges close during this time for their yearly maintenance. There are still some river crossings that can be dangerous to cross during the rains. 

EcoSystems on the Osa Peninsula

Storm over Corcovado on the Osa

Highest Point on the Osa (meters)

Longest hours of sunlight are in June

Shortest hours of sunlight are in December

Most days with some rain is in October

Least days with some rain is in February

Storm over the Golfo Dulce
Big Storm over the golfo dulce
Storm over the golfo dulce


The Weather of the Osa Peninsula

December to April

Averge Daily HIGH Temperature

90 Degrees Fahrenheit

29 Degrees Celsius

Average Monthly Rainfall – 8.6 cms

May to September

Averge Daily HIGH Temperature

85 Degrees Fahrenheit

28 Degrees Celsius

Average Monthly Rainfall – 50  cms

October and November

Averge Daily HIGH Temperature

82 Degrees Fahrenheit

27 Degrees Celsius

Average Monthly Rainfall – 63.5 cms


The sunniest days on the Osa Peninsula are in February which has the most hours of sunshine per day with an average of 7.8 hours of sunshine per day. October has the least sunshine with an average of 4.7 hours of sunshine per day.

The wettest month on the peninsula is October with the most days of rain (18.5 days with some rain).
The driest month on the Osa is February with the least days of rain (2.3 days with some rain).

The ultraviolet index is the highest in April (15.1) and lowest in December (10.7).
A reading above 11 indicates an extreme risk of harm from unprotected sun exposure.

Osa Peninsula Map Beaches


Up-To-Date Tourist Information from the Osa Peninsula

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