Last updated: August 21, 2025
In September, Nicoya, Costa Rica, experiences a tropical climate characterized by warm temperatures and significant precipitation. With a maximum of 34°C (93°F) and an average temperature of 26°C (79°F), the days remain generally warm, while nights cool down to a minimum of 22°C (71°F). This month sees a considerable rainfall, accumulating to 353 mm (13.9 in) over 28 rainy days, creating lush landscapes and vibrant flora. The humidity levels hover around 80%, contributing to the region's characteristic tropical feel, making September an enchanting yet rainy time for visitors and locals alike.
In September, Nicoya, Costa Rica, experiences a slight dip in temperatures as the rainy season unfolds. With a minimum of 22°C (71°F) and a maximum of 34°C (93°F), the days remain warm yet more comfortable than the peak of the dry season. The average temperature settles at 26°C (79°F), reflecting the trend of cooler days compared to the preceding months. As the region transitions from summer to autumn, the humidity increases, creating a lush, vibrant landscape that complements the warm days with refreshing evening breezes. This period invites travelers to enjoy the beautiful natural scenery, all while reveling in the pleasantly moderated warmth characteristic of this captivating coastal destination.
September marks a peak in precipitation for Nicoya, Costa Rica, with 353 mm (13.9 in) of rain falling over 28 days. This month stands out in the rainy season, closely following August's totals and setting the stage for October's even higher rainfall. The intensity of September’s downpours illustrates a transition where the region's lush landscapes come alive, sustaining vibrant flora and fauna. As the dry months give way to heavy rains, this pattern highlights the importance of September as a vital period for replenishing water sources and nurturing the local ecosystem. The rhythm of rainfall illustrates nature’s cycle, with each drop contributing to the rich biodiversity that defines Costa Rica.
In September, Nicoya, Costa Rica, experiences a notable shift in humidity, with levels averaging 80%. This marks a peak in moisture as the region transitions into the rainy season. Following the drier months of the year, where humidity hovers between 63% and 66% from January to April, the onset of the wet season brings a significant increase. The humidity steadily climbs, reaching its zenith in July at 85%, gradually tapering off to 79% by October. September serves as a culmination of this upward trend, embodying the lush vitality of the region as rainfall nurtures its vibrant ecosystems, making it a fascinating time to experience the verdant landscapes of Nicoya.
In September, Nicoya, Costa Rica, maintains a notable UV Index of 13, categorizing it as extreme and keeping the burn time at a quick 10 minutes. This trend of high UV exposure is consistent throughout the year, particularly from January through August, where the index frequently peaks at 14. As the seasons change into October and November, the UV Index slightly dips to 13 and 11, respectively, offering a brief respite before settling into a very high level of 10 in December. Visitors and locals alike should remain vigilant, as the intensity of the sun remains a prominent feature in Nicoya's tropical climate. For more details on safeguarding against UV exposure, check out Nicoya UV Index.
UV Risk Categories
As September arrives in Nicoya, Costa Rica, the sun continues to shine brightly, offering 268 hours of glorious sunlight this month. While this is a slight dip from the summer highs of July and August, which boast 312 and 278 hours respectively, it remains a favorable time for sun enthusiasts. The trend of decreasing daylight hours throughout the year is evident, with September's sunshine leading into a notable decline in October at 245 hours. However, the energy of the sun is still felt, as it lingers warmly before transitioning into the increasingly shorter days of fall. As locals and visitors alike bask in September's rays, it serves as a reminder of the vibrant natural beauty that Nicoya has to offer year-round.
In Nicoya, Costa Rica, the likelihood of sunny weather dramatically shifts throughout the year, and September is positioned as one of the cloudiest months. With only a 13% chance of sunshine, this month typically sees the region transitioning between the heavy rains of the green season and the upcoming drier months. Following the peak of sunny days in January and December—where the chances soar to 60% and 72%, respectively—September stands out as a time when overcast skies and rainfall prevail, reflecting a broader trend of diminishing sunshine during the rainy season. As the year progresses, once we reach November, the likelihood begins to improve again, suggesting a welcomed return of sunshine.
In September, Nicoya, Costa Rica, enjoys 12 hours of daylight, consistent with the preceding months of June through August, where daylight duration remained steady at this generous length. This balance of light allows for plenty of opportunities to soak up the sun and immerse in the region's vibrant nature. Following this month, daylight will gradually decrease to 11 hours in the following months, signaling the transition into the year's end. Overall, September showcases a continued trend of ample daylight that characterizes the region's lush environment and encourages outdoor adventures, making it an ideal time to explore Nicoya's breathtaking landscapes.
In September, the winds in Nicoya, Costa Rica, gently whisper at an average speed of just 1.3 m/s (3 mph), akin to a soft breath of fresh air that slows the pace of life. This month marks one of the calmest periods of the year, following a trend of decreasing wind speeds that began in June. As the dry season approaches, the winds rise again, but September’s tranquility mirrors the peaceful ambiance of the region. With the lush landscapes and picturesque beaches, it's a perfect time for those seeking a serene escape, allowing visitors to fully immerse themselves in the natural beauty without the constant rush of stronger winds.
Weather in Nicoya varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Nicoya, focusing on differences in temperature, rainfall, humidity, and UV levels.
In September, the weather is typically hot and humid, with average temperatures ranging from a minimum of 22°C (71°F) to a maximum of 34°C (93°F), and a significant amount of rainfall at 353 mm (13.9 in) spread over 28 days. The humidity levels are quite high at 80%, making the atmosphere feel even warmer. In contrast, January offers a different experience with a minimum temperature of 17°C (64°F), an average of 27°C (81°F), and a peak of 36°C (97°F). The month is characterized by a sharp reduction in rainfall, with only 12 mm (0.5 in) occurring over just 2 days, and humidity dropping to 66%. This makes January a drier and more comfortable time to enjoy outdoor activities. For more detailed insights, check out Nicoya weather in January.
In comparing the weather of September and February, we see notable differences in temperature and precipitation. September experiences a milder average of 26°C (79°F), with maximum temperatures reaching up to 34°C (93°F) and a high level of humidity at 80%. This month also sees significant rainfall, accumulating 353 mm (13.9 in) over 28 days. In contrast, February boasts warmer temperatures, with an average of 28°C (82°F) and peak highs reaching 37°C (99°F). Remarkably, February is much drier, receiving only 2 mm (0.1 in) of rain over the course of the month, and enjoys lower humidity levels at 64%. For more details, you can check Nicoya weather in February.
When comparing the weather in September and March, it is evident that March tends to be significantly drier and hotter. In September, temperatures range from a minimum of 22°C (71°F) to a maximum of 34°C (93°F), with an average of 26°C (79°F) and high humidity at 80%. Additionally, September experiences considerable rainfall, totaling 353 mm (13.9 in) over 28 days. In contrast, March boasts warmer temperatures, with a minimum of 20°C (69°F) and a maximum rising to 37°C (99°F), along with a much higher average of 28°C (83°F). The month is remarkably dry, seeing only 4 mm (0.1 in) of precipitation across 0 days and lower humidity at 63%. For more specific insights, you can check out Nicoya weather in March.
In comparing the weather of September and April, notable differences emerge. September tends to be cooler with average temperatures ranging from a minimum of 22°C (71°F) to a maximum of 34°C (93°F), while April experiences warmer conditions, averaging between 22°C (71°F) and peaking at 39°C (102°F). Precipitation in September is significantly higher at 353 mm (13.9 inches) over 28 days, compared to just 51 mm (2.0 inches) across 9 days in April. Additionally, September's humidity remains high at 80%, whereas April has a more comfortable level of 63%. For a deeper dive into April weather, you can visit Nicoya weather in April.
In comparing the weather between September and May, we see notable differences in temperature and humidity. September has a minimum temperature of 22°C, with an average of 26°C and a maximum of 34°C, accompanied by high humidity at 80%. This month also experiences significant precipitation, totaling 353 mm over 28 days. In contrast, May boasts slightly higher temperatures, with a minimum of 23°C, an average of 28°C, and a maximum reaching 38°C. However, May's humidity is lower at 63% and has less rainfall, totaling 286 mm over 22 days. For more detailed insights on May weather, you can visit Nicoya weather in May.
When comparing the weather in September and June, both months feature similar minimum temperatures around 22°C (71-72°F), but June tends to be slightly warmer overall, with average temperatures reaching 27°C (80°F) and a maximum of 36°C (97°F), compared to September's averages of 26°C (79°F) and a maximum of 34°C (93°F). Precipitation levels are quite comparable, with September receiving 353 mm (13.9 in) over 28 days and June just slightly higher at 359 mm (14.1 in) over 26 days. Humidity levels are higher in September at 80%, while June's humidity is a bit lower at 74%. For more specifics on the weather conditions in June, you can check Nicoya weather in June.
When comparing the weather in September to that in July, we see some notable differences. September tends to be slightly cooler, with an average temperature of 26°C (79°F) compared to July's 27°C (80°F). However, September experiences higher humidity levels at 80%, compared to July's 85%. Precipitation is significantly greater in September, totaling 353 mm (13.9 in) over 28 days, while July's rainfall is lower at 215 mm (8.4 in) over 23 days. This contrast highlights September as a wetter month, making July a more favorable time for outdoor activities. For a detailed look at the July weather, check out Nicoya weather in July.
In comparing the weather of September and August, both months present similar temperature ranges, with minimums around 22°C (71°F) and average temperatures of 26°C (79°F in September and 80°F in August). However, August tends to be slightly warmer with a maximum temperature of 35°C (95°F), compared to September's peak of 34°C (93°F). Precipitation is notably higher in September, totaling 353 mm (13.9 in) over 28 days, compared to August's 290 mm (11.4 in) over 25 days. Humidity levels are similar, with September at 80% and August at 82%. For more detailed insights on August conditions, visit Nicoya weather in August.
In comparing the weather between September and October, we see slight variations in temperature and precipitation. September features a minimum temperature of 22°C (71°F), averaging 26°C (79°F), and peaking at 34°C (93°F), while October's temperatures range from a minimum of 21°C (71°F) to an average of 26°C (79°F) and a maximum of 33°C (92°F). Precipitation levels are notably higher in October, with 407 mm (16.0 in) falling across 29 days compared to September's 353 mm (13.9 in) over 28 days. Humidity remains relatively consistent, slightly dipping from 80% in September to 79% in October. For more detailed information about October weather, you can refer to Nicoya weather in October.
September and November showcase a transition in weather patterns, though both months maintain a warm average temperature of 26°C (79°F). September tends to be more humid, with a higher minimum temperature of 22°C (71°F) compared to November's 20°C (68°F). Rainfall is significantly greater in September, with 353 mm (13.9 in) spread over 28 days, while November sees a notable decrease to 130 mm (5.1 in) over just 15 days. This reduction in precipitation and humidity during November makes it a drier and slightly cooler month, which can be ideal for outdoor activities. For more details, you can check Nicoya weather in November.
In comparing September and December weather, one can observe marked differences in both temperature and precipitation levels. September experiences higher humidity at 80% and significantly more rainfall, with about 353 mm falling over 28 days, resulting in a much wetter atmosphere. The average temperature in September is 26°C (79°F), with a maximum of 34°C (93°F), creating a warm, humid environment.
In contrast, December offers a slightly drier climate, with only 31 mm of rain over just 4 days and a lower humidity level of 70%. The temperatures remain warm as well, averaging 27°C (80°F) and peaking at 35°C (95°F). For those interested in understanding the specifics of December weather, further details can be found here: Nicoya weather in December.
September in Nicoya brings a shift marked by high humidity and frequent rainfall, creating a lush and vibrant landscape that distinguishes it from other months. With temperatures that maintain a warm average, it’s a time when the pleasant heat combines with daily showers, setting a cozy ambiance. The constant precipitation—often manifesting through brief but intense downpours—creates a dynamic atmosphere, making it the wettest month of the year. For those looking to experience the beauty of nature in full bloom, September’s distinct weather offers a unique charm that beckons adventure. Discover more about the diverse Nicoya Climate and what makes each month special.