September in Costa Rica is deep into the rainy season which spans from May to mid-November. There are a number of benefits to traveling during this time: lower prices and fewer crowds (more on this below), and the fact that Costa Rica's already lush vegetation becomes even more vibrant.
Sure, there's more of a chance of rains clouding the skies on your beach holiday, but the tradeoff is that the tropical dry heat found in certain parts of the country (like the Nicoya Peninsula) is a bit more bearable. The popular surf village of Tamarindo, for example, enjoys averages in the 70s Fahrenheit during the rainy season as opposed to the 80s or even higher. Costa Rica's rainy season can be so pleasant, in fact, that locals have taken to calling it the "green season." Read our guide for visiting Costa Rica in the rainy season.
Crowds & Costs
Because September falls in Costa Rica's offseason, you can expect fewer tourists and all the benefits that come along with it, like reduced hotel room prices and cheaper international airfares (and some cheaper local flights, too). That said, because September is also the time of the country's Independence Day, expect huge crowds of locals in cities and towns from the middle of the month onward. Overall it's a great party, but it might slow down your transport times if you're driving through such places.
Where to Go
Some parts of Costa Rica remain drizzly and overcast all year. Nowhere is this more striking than at the Monteverde Cloud Forest Biological Reserve, a 26,000-acre protected area filled with hiking trails and suspension bridges. Or head to the Caribbean coast for some sunshine and surfing—Puerto Viejo has a rich Afro-Caribbean heritage, as well as some great surf breaks (particularly at Salsa Brava beach). And Guanacaste Province is an area that remains reliably hot and dry all year—there's very little rainfall even in the rainy season.
If your trip coincides with Independence Day (9/15), then you can go anywhere and enjoy the festivities. It's a colorful, raucous affair with people adorning cars, homes, and businesses with the Costa Rican flag. Celebrations kick off with the Desfile de Faroles, a night parade of children carrying homemade lanterns. Cartago, located just outside San José, is the final destination of a symbolic independence torch that is literally carried by relay runners all the way from Guatemala. Needless to say, the parades and parties here are epic.
What to Do
If there's one activity tailor-made for Costa Rica's green season, it's rafting. By June, the rivers are raging and the greenery along the banks is in full bloom. That's not to say the only options are for adrenaline junkies (like the wild class IV rapids on Reventazon River)—the Savegre River, which passes through Manuel Antonio National Park, features class II and III rapids ideal for kids as young as eight.
For whale watching, head to the Osa Peninsula. Just offshore from Bahía Drake, humpback whales migrating from the south pass by during the months of July to November. In this area you can see them engaged in mating or, if you're lucky, giving birth to calves. And your best chance to view nesting turtles is during the green season, too. From July to December (and most frequently in September-November), thousands of female turtles crawl up on the beach to lay their eggs. Try the Ostional Wildlife Refuge and Tortuguero National Park, on the northern Caribbean coast.
Events in September
Independence Day. September 15th is CostaRica's Independence Day (they officially achieved it in 1821), and ticos celebrate in style. They don traditional dress and parade through the streets in most cities and towns throughout the country.
International Coastal Clean-Up Day. In mid-September, the Ocean Conservancy spearheads efforts to tackle coastal pollution by sponsoring volunteers to clean up local beaches.
Traveling to Costa Rica in September? Check out these great itineraries.
Caribbean Coast Adventure. Spend a fun-filled week hiking in the rainforest, snorkeling in coral reefs, rafting the world-class rapids of Río Pacuare, and more. This itinerary is ideal for travelers heading to Costa Rica during the "green season" (May - November), as the Caribbean coast stays relatively dry during rainy months—and it's also the best time to see turtles nesting in Tortuguero National Park
Costa Rica Whitewater and Surfing. From a whitewater rafting adventure along miles of tropical scenery on the Pacuare River to an excursion to one of the country's top surf spots, this short and sweet itinerary is jam-packed with thrilling aquatic experiences.