September falls within Costa Rica’s “green season,” also known as the rainy season. Characteristically, this period experiences significant rainfall, particularly in the afternoons and evenings. However, mornings are often sunny, providing a mix of weather conditions. Temperatures remain warm, typically ranging from the mid-70s to the mid-80s Fahrenheit (low 20s to high 20s Celsius). Humidity levels are also high.
Understanding Costa Rica’s climate during this month is essential for travelers planning a visit. The green season offers unique advantages, including lush landscapes, fewer crowds, and lower prices on accommodations and tours. The vibrant flora and fauna thrive in the rainy season, providing a different perspective on the country’s biodiversity. Historically, this period has been important for agricultural cycles, replenishing water resources and supporting the growth of various crops vital to the local economy.