Costa Rica’s September Weather: Average Temperatures, Rainfall, & Hurricane Threat

Because Costa Rica is so close to the equator, it has a tropical climate that doesn’t experience winter seasons. In fact, Costa Rica’s weather basically only has two seasons: dry season and wet season. And because of the consistent, pleasant weather all year round, it is a favored destination for tourism. Thinking of visiting in September? Find out about Costa Rica’s average weather in September, including temperatures, rainfall, and hurricane threat.

Costa Rica’s Average Temperatures in September

Given the geographical diversity in Costa Rica, it is hard to pinpoint an average temperature for the entire country. With the mountain ranges, valleys, the Pacific Ocean to the west, and the Caribbean Sea to the east, many aspects affect Costa Rica’s weather patterns and temperatures.

For instance, in San José, the capital of Costa Rica, average highs for September are around 77°F. It’s uncommon for days to get above 81°F. Average lows in San José are around 63°F and rarely below 61°F. San José is situated in the middle of the country and experiences temperatures of 64°F and 78°F all year round.

However, in Santa Cruz, which is situated in the Nicoya Peninsula, daily highs are around 77°F and lows around 63°F. Usually, in September, it never goes over 81°F or falls below 61°F. Year-round, temperatures hover between 74°F and 99°F. This part of Costa Rica averages higher temperatures because of the high humidity and high number of sunny days the Nicoya Peninsula sees.

While in general, most of the country is a tropical paradise, even in September, the mountain ranges can get chilly. For instance, Mount Chirripò can be 39°F to 64°F during the day and dip below freezing at night.

Costa Rica’s Average Humidity in September

While Costa Rica’s temperatures are quite pleasant in September, they also come with high humidity. San José has 80 percent humidity on average during the month of September, while the Nicoya Peninsula experiences 83 percent humidity. Quesada, which is a city northwest of San José, has the highest humidity in September at 92 percent. Because September and October are the rainiest months in Costa Rica, the moisture makes for very muggy, humid days.

Average September Rainfall

As mentioned, September is one of the rainiest months in Costa Rica. Typically, the country sees 20 to 30 centimeters of rain throughout the month. The wet season in Costa Rica lasts from May to November, with September and October being the wettest. Then the dry season settles in from December to April.

Hurricanes in September

Usually, hurricane season in Costa Rica lasts from the end of May to November. The peak hurricane times are in October and November. However, hurricane risk is low for Costa Rica as it is south of the hurricane belt. Since 1887, only two hurricanes have hit Costa Rica in September. But, the region does experience many tropical storms.

Visiting Costa Rica in September

While there is a low risk of hurricanes when you visit Costa Rica in September, other factors make the month less enjoyable. With September being the peak of the wet season, be prepared to make rainy-day plans. The precipitation hinders the amount of outdoor recreation you may enjoy. Plus, the high humidity makes nature adventures a bit unpleasant.

However, while most of the country is in a deluge of tropical storms, the Caribbean coast actually has clear weather. Because the Caribbean coast has an earlier wet season, September and October are dry months for the coast.

Also, September is during turtle nesting season. Green sea turtles and loggerheads typically come to shore from July to October to lay eggs. The Northern Caribbean is famous as a sea turtle nesting site in Costa Rica, and September is a fantastic time to spot a nesting mother turtle.

Cheaper Travel in Costa Rica for September

Because it is so rainy, tourism is low in Costa Rica during this time. This means booking a hotel or tour is simple, as there’s not much demand. Plus, prices are often discounted on the Pacific side. However, because September is the peak season for the Caribbean coast, you won’t see many price breaks. But don’t let that stop you from experiencing the sunny beaches and whale-watching opportunities on the Caribbean coast. All in all, if you don’t mind the unpredictable weather, September can be a fantastic time to visit Costa Rica.