Last updated: August 21, 2025
September in La Fortuna, Costa Rica is characterized by warm temperatures and high humidity, creating a lush, vibrant atmosphere. With a maximum temperature reaching 31°C (88°F) and an average of 24°C (75°F), visitors can expect tropical warmth throughout the month. However, the minimum temperature can dip to 20°C (68°F), providing some cooler respite. This month sees significant rainfall, with precipitation totals reaching 277 mm (10.9 in) across nearly all 29 days, contributing to the region's stunning natural beauty. The humidity level hovers at a notable 84%, enhancing the feeling of being enveloped in the rainforest's rich embrace.
In September, La Fortuna experiences a tropical climate characterized by mild temperatures and high humidity. The monthly averages settle at a steady 24°C (75°F), reflecting a delightful balance of warmth without the extremes of summer. The daytime highs reach a pleasant 31°C (88°F), while nighttime temperatures remain comfortable, dipping to a minimum of 20°C (68°F). This month continues the trend of warm and consistent weather seen earlier in the year, with temperatures gradually shifting towards slightly cooler averages as the year progresses. Rainfall tends to increase during September, adding a refreshing touch to the lush green landscape, making it an enchanting time to explore La Fortuna's natural beauty.
In September, La Fortuna experiences a noteworthy increase in precipitation, with 277 mm (10.9 in) of rainfall over 29 days. This pattern continues the trend of the preceding months, where the region sees a significant amount of rain, particularly during the wet season. While September's rainfall slightly dips compared to the extremes of October (398 mm) and June (312 mm), it remains robust, sustaining the lush landscape that defines this area. The consistent precipitation across numerous days reflects the typical tropical climate, making September one of the key months for nature enthusiasts who come to witness the thriving flora and fauna fueled by this abundant rainfall.
In September, La Fortuna experiences a notable humidity level of 84%, marking it as one of the wetter months of the year. This month follows a trend of increasingly high humidity that begins in mid-year, with July peaking at an impressive 88%. While humidity slightly decreases from August's 85%, September remains comfortably humid, embodying the tropical charm of Costa Rica. Overall, the humidity levels within La Fortuna reflect a greater tendency towards moisture as the year progresses, particularly during the rainy season from June to October, making it a lush paradise for nature lovers and adventurers alike.
In September, La Fortuna, Costa Rica, continues to experience a consistently high UV Index, registering at 13, which falls within the extreme exposure category. This trend maintains the pattern seen throughout the year, where the UV Index regularly peaks, particularly from March to April at 15. With a burn time of just 10 minutes across the board during these months, caution is paramount for outdoor enthusiasts. As we transition into the drier season, the UV Index remains a vital consideration, joining the ranks of previous months like August and October. For those looking to stay informed about UV exposure in this beautiful region, detailed information can be found at La Fortuna UV Index.
UV Risk Categories
September in La Fortuna, Costa Rica, offers a delightful balance of sunshine and scenic beauty, with an average of 250 hours of sunshine. This marks a slight dip from the vibrant summer months, particularly from the peak of March with 330 hours, where sunshine graces the landscape generously. As the region transitions from the mid-year rainy season, September's sunshine provides a perfect opportunity for outdoor adventures amid lush greenery. Following September, October experiences a further reduction to 232 hours, hinting at the retreat of the dry season. Overall, while sunlight hours may lessen slightly in September, the enchanting atmosphere and vibrant surroundings continue to captivate visitors seeking an unforgettable experience.
In La Fortuna, Costa Rica, September represents one of the lowest probabilities of sunny weather, with only an 11% chance of sunshine. This decline in sunny days is part of a broader trend seen from April through August, where the likelihood of clear skies diminishes dramatically, reaching its nadir in August at just 7%. As the rainy season peaks, travelers might want to consider the preceding months when sunshine is more abundant, notably February and March, each boasting a 42% chance of sunny weather. As such, if you're hoping for bright, clear days, it may be wise to plan your visit outside of September, when the embrace of rain clouds is at its strongest.
In September, La Fortuna, Costa Rica, enjoys a consistent 12 hours of daylight, mirroring the trend established in the preceding months. As the region approaches the end of the rainy season, the enduring daylight duration provides ample opportunity for exploration and adventure amidst its lush landscapes. Early in the year, both January and February feature slightly shorter days with 11 hours of daylight, but as spring progresses into the warmer months—March through August—daylight extends to a gratifying 12 hours. This steady pattern continues through September, offering travelers a perfect blend of vibrant daylight and rich biodiversity before the days gradually shorten again in October.
In September, La Fortuna experiences some of the calmest winds of the year, with average speeds plummeting to just 1.4 m/s (3 mph). This tranquil atmosphere typically signals the peak of the rainy season, where the lush landscapes and vibrant wildlife thrive under the cooling showers. As the month progresses, the gentler breezes create a serene backdrop, perfect for soaking in the natural beauty and engaging in leisurely pursuits. Comparing this to the earlier months of the year, where winds reached higher speeds, it's evident that September marks a significant lull, embracing a more relaxed and peaceful climate that invites reflection and appreciation of Costa Rica’s stunning surroundings.
Weather in La Fortuna varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in La Fortuna, focusing on differences in temperature, rainfall, humidity, and UV levels.
In September, the weather is notably warmer and more humid, with temperatures ranging from a minimum of 20°C (68°F) to a maximum of 31°C (88°F), and an average of 24°C (75°F). This month also experiences significant rainfall, with a total precipitation of 277 mm (10.9 in) spread over 29 days, resulting in a high humidity level of 84%. In contrast, January offers a slightly cooler and drier climate, with temperatures ranging from a minimum of 16°C (61°F) to a maximum of 29°C (84°F), averaging at 22°C (72°F). Precipitation during this month is much lower, totaling 99 mm (3.9 in) across 13 days, and the humidity drops to a more comfortable 71%. For more detailed information on the weather in January, you can check La Fortuna weather in January.
When comparing the weather between September and February, notable differences emerge. September experiences a warmer average temperature of 24°C (75°F) with highs reaching 31°C (88°F) and a high humidity level of 84%. However, it is also characterized by significant rainfall, boasting 277 mm (10.9 in) over 29 days. In contrast, February presents a slightly cooler average temperature of 23°C (73°F), with the same maximum of 31°C (88°F), but a much drier atmosphere with only 23 mm (0.9 in) of precipitation over just 5 days and lower humidity at 70%. For more specific details about the weather in February, check out La Fortuna weather in February.
In September, the weather tends to be warmer and more humid than in March, with average temperatures ranging from a minimum of 20°C (68°F) to a maximum of 31°C (88°F) and a high humidity level of 84%. This month also experiences significant rainfall, with 277 mm (10.9 in) of precipitation over 29 days. In contrast, March showcases slightly cooler temperatures, with averages between 17°C (63°F) and 30°C (87°F), lower humidity at 68%, and a much drier climate, receiving only 28 mm (1.1 in) of rain across just 6 days. For further details on the weather in March, you can check La Fortuna weather in March.
When comparing the weather in September and April, it is clear that September is generally wetter and more humid. While September has an average temperature of 24°C (75°F), similar to April's average of 24°C (76°F), the minimum and maximum temperatures in April are slightly lower, ranging from 17°C (64°F) to 32°C (90°F) compared to September’s 20°C (68°F) to 31°C (88°F). Notably, September experiences a significant amount of rainfall, with 277 mm (10.9 in) of precipitation over 29 days, whereas April sees much less rain at 72 mm (2.8 in) throughout only 13 days. This makes September a much more humid month, with humidity levels reaching 84% compared to April’s 69%. For more details, you can check La Fortuna weather in April.
In comparing the weather of September and May, both months exhibit warm average temperatures, with September showing slightly cooler minimums at 20°C (68°F) compared to May's 19°C (67°F). However, May tends to reach a higher maximum temperature of 32°C (91°F), just exceeding September's peak of 31°C (88°F). When it comes to precipitation, May experiences marginally more at 308 mm (12.1 in) over 26 rainy days, while September has 277 mm (10.9 in) across 29 days, resulting in a wetter ambiance with higher humidity in September at 84%, compared to May's 70%. For more detailed insights into May's weather conditions, you can explore La Fortuna weather in May.
Both September and June share similar temperature ranges, with minimums around 20°C (68°F), averages of approximately 24°C (75°F-76°F), and maximums reaching up to 31°C (88°F). However, September typically experiences slightly less precipitation at 277 mm (10.9 in) compared to June's 312 mm (12.3 in), despite both months featuring rainfall on about 29 days. Humidity levels are also quite comparable, with September at 84% and June at 81%. For more detailed information on June weather, visit La Fortuna weather in June.
In comparing the weather of September and July, both months exhibit similar temperature ranges with a minimum of 20°C (68°F) and an average of 24°C (75°F). However, September tends to be slightly warmer on average, reaching a maximum of 31°C (88°F), compared to July's peak of 30°C (87°F). Precipitation levels are notably higher in September, with 277 mm (10.9 in) falling over 29 days, whereas July has 253 mm (10.0 in) over 28 days. Additionally, the humidity in September is slightly lower at 84%, compared to July's higher humidity level of 88%. For more detailed weather information, you can check La Fortuna weather in July.
In comparing the weather between September and August, both months experience similar temperature ranges with minimums at 20°C (68°F), averages at 24°C (75°F), and maximums reaching 31°C (88°F for September and 89°F for August). However, September sees slightly less precipitation at 277 mm (10.9 in) compared to August's 295 mm (11.6 in), despite both months experiencing rainfall on 29 days. Humidity levels are also quite comparable, with September at 84% and August at 85%. For more detailed information on temperature and conditions, you can visit La Fortuna weather in August.
In September, the weather features temperatures ranging from a minimum of 20°C (68°F) to a maximum of 31°C (88°F), with an average temperature of 24°C (75°F). However, this month is marked by significant precipitation, totaling 277 mm (10.9 in) over 29 days and high humidity at 84%.
In contrast, October's weather presents a slightly cooler maximum temperature of 30°C (86°F), while maintaining the same minimum and average temperatures. One notable difference is the increase in precipitation, reaching 398 mm (15.7 in) across the same number of days, along with a marginally lower humidity of 82%. For more details on October weather specifically, you can visit La Fortuna weather in October.
In comparing the weather between September and November, we see a slight decrease in both temperature and humidity. September experiences a minimum temperature of 20°C (68°F) and an average of 24°C (75°F), peaking at 31°C (88°F), while November's temperatures are slightly lower, with a minimum of 19°C (66°F) and an average of 23°C (74°F), reaching a maximum of 29°C (84°F). Precipitation also diminishes, with September receiving 277 mm (10.9 in) over 29 days compared to November's 259 mm (10.2 in) over 27 days. The humidity decreases from 84% in September to 81% in November, making November a slightly drier and cooler month overall. For a detailed look at the weather specifics, visit La Fortuna weather in November.
In September, the weather is noticeably warmer and more humid, with average temperatures ranging from a minimum of 20°C (68°F) to a maximum of 31°C (88°F). The month also experiences significant rainfall, averaging 277 mm (10.9 in) over 29 days, resulting in a high humidity level of 84%. In contrast, December sees slightly cooler temperatures, with averages between 17°C (63°F) and 29°C (84°F), and less rainfall at 180 mm (7.1 in) across 22 days. The humidity decreases to 74%, making December feel more comfortable overall. For a detailed overview of weather conditions, you can check La Fortuna weather in December.
September in La Fortuna presents a unique weather experience, characterized by higher humidity and frequent rain. With a notable increase in precipitation, this month often feels lush and vibrant compared to the drier months, making it an ideal time for those who appreciate the green scenery and thriving wildlife. While temperatures remain warm, the near-constant cloud cover can provide a respite from the intense sun, creating a refreshing atmosphere. For those looking to explore the natural beauty of the area, it's the perfect opportunity to witness the region in its full splendor. To learn more about the weather throughout the year, visit La Fortuna Climate.