Costa Rica Weather in September 2025: Height of the Rainy Season

It continues to be wet in Costa Rica during September, with the month sitting smack-dab in the middle of the country's rainy season which lasts from May to November. While the Caribbean coast will see plenty of sunshine during this time, other parts of the country will remain rainy, lush, and gorgeously green. Temperatures, on the whole, will start to cool off towards the end of the month as well. Average September temperatures are expected to range from highs that touch 30°C (86°F) and lows that are closer to 16°C (61°F).

September, being a rainier month in Costa Rica, is part of the country's tourist off-season. This means it's quieter and less crowded, and you'll have the added advantage of having to pay a lot less than you would during the first few months of the year insofar as accommodation and airfare are concerned. While most of the month is quiet and not crowded at all, Independence Day in the middle of the month sees a lot of people make their way to the cities to take in the celebrations, and this can lead to congestion and traffic issues.

Except for the Caribbean side, it's rainy in most other parts of Costa Rica during September. In order to have as enjoyable a time as possible, and be prepared for all weather conditions, make sure your packing list includes plenty of quick-drying tops and shorts, lightweight pants or capris, swimwear if you plan on spending time on the beaches on the Caribbean side, reef shoes, durable tennis shoes, sturdy sandals, a good quality raincoat or poncho, insect repellent, sunscreen, sunglasses, hats, and binoculars for wildlife spotting.

To better understand what Costa Rica is like when it comes to climate and weather conditions during the month of September, continue reading below.

Costa Rica Weather in September: Overview

• Average temperature range: 16°C (61°F) – 30°C (86°F)
• Rainfall: 450 mm (18 inches) in San Jose; 800 mm (31 inches) in Manuel Antonio; 300 mm (12 inches) in Puerto Viejo.
• Rainy days: 22 in San Jose; 21 in Manuel Antonio; 21 in Puerto Viejo.

Costa Rica is rarely hit by the hurricanes that form in the region during this time of year. This is largely due to the country's unique latitudinal position. That said, given the potential seriousness – and the possible dangers – that go hand in hand with hurricanes and tropical storms, it's always wise to think ahead and stay prepared by checking local and national weather forecasts whenever possible. This will help you stay on top of any adverse weather developments.

Average temperatures for September differ from region to region in Costa Rica. Temperatures range from maximums of 24°C (75°F) in San Jose, 28°C (82°F) in Manuel Antonio, and 29°C (84°F) in Puerto Viejo. On the other hand, minimum temperatures are around 16°C (61°F) in San Jose, 23°C (73°F) in Manuel Antonio, and 24°C (75°F) in Puerto Viejo.

There are many reasons in favor of visiting Costa Rica during the month of September. For one thing, the weather during this time affords you the unique possibility of choosing whether you want to spend time sunbathing on the Caribbean side of the country, or whether recharging your batteries in the lush and rainy calm of the country's evergreen rainforests is more your idea of a relaxing time. Moreover, September 15th is Costa Rica's Independence Day, and this is a fascinating and extremely fun holiday to celebrate with the locals there.  

Weather of Costa Rica's Major Cities in September

Best Places to Visit in Costa Rica in September

1.Isla del Cano Biological Reserve

Located only a short distance from Drake Bay in the Osa Peninsula, Isla del Cano Biological Reserve came into existence in 1978. Since then, the government has taken many steps in making sure the island's natural and indigenous heritage remains protected. Isla del Cano Island is home to many species of flora including orchids, cacao, and figs, and an equally astounding number of fauna including frogs, foxes, and fishes.

Despite the rains that decrease water visibility, what makes this month of the year a fabulous time to visit Isla del Cano is the fact that the whales make their annual migration during September. This is a sight to behold because if you're lucky, you'll get to see them mate or give birth.

2.San Jose

San Jose is wonderful weather-wise during September. While it certainly does rain, it's nice and cool during the month. The capital is home to some amazing dining and nightlife options, not to mention cultural attractions. What's more, 15th September marks Costa Rica's Independence Day, with some of the best and grandest celebrations for this special celebration taking place in the country's capital city. If you're in San Jose during the middle of the month, you'll see many a parade, party, and national ceremony taking place to mark the occasion.

3.Puerto Viejo

Puerto Viejo is nestled away on the Caribbean side of the country, far from the September rains that envelop much of the Pacific side, meaning it's relatively dry and sunny. So, if you're in the mood to spend some time on the beach and take in the sun, this is the place to be in. You can spend hours swimming, snorkeling, and biking around this beautiful stretch of sand and good vibes!

September Crowds and Costs

September remains smack-dab in the middle of Costa Rica's rainy season, and is, as a result, also very much part of the country's tourist off-season. This means fewer tourists and cheaper costs no matter where you are in this Central American republic. It's quieter during these rainier months, and you can find great discounts when it comes to accommodation and airfare.

The only exception to this is the time around Costa Rica's Independence Day in the middle of September. Independence Day itself and the days before and after it see huge crowds of locals and tourists alike in the cities and this can lead to congestion and traffic in the downtown areas. It's a great time, though, and something you ought not miss if possible.

September Events in Costa Rica

Independence Day: Costa Rica declared its independence from Spain on 15 September 1821, and celebrations on the same day today include nationwide displays of parades and parties. The best of these is in and around the capital of San Jose but honestly, the festivities take place throughout the country. Get ready to party with the locals with some great traditional food, fireworks, all-day dancing, parades, and flag-raising and torch-lighting ceremonies!

What to Wear in Costa Rica in September

Apart from the Caribbean side, it's quite rainy throughout most of Costa Rica during September. This doesn't mean you can't have a splendid time if you're visiting the country during this time of the year. With a little preparation, you'll be well equipped to tackle both the rains and the sunshine with equal ease.

Make sure your packing list includes the following items if you're traveling to Costa Rica in September: quick-drying tops and shorts, a good quality raincoat or poncho, sandals, durable tennis shoes, lightweight pants or capris (these also help in keeping mosquitos at bay), insect repellent, sunscreen, sunglasses, hats, swimwear if you plan on hitting the beaches on the Caribbean side, reef shoes, and a pair of binoculars for wildlife spotting.

Explore Costa Rica with Global Highlights

If you're reading this, you're probably planning your dream vacation to gorgeous Costa Rica!  That's just perfect because our travel experts here at Global Highlights go above and beyond in making sure your itinerary is as well planned yet personal as you like. We take immense pride in making sure you have a memorable time in Costa Rica, and we use our expertise and attention to detail to curate trips for you and your loved ones that are both unique and dreamy. We'll keep everything from weather conditions to special interests in mind, so that you can just relax and take in the good times!