September Weather in Quepos, Costa Rica

Last updated: August 21, 2025

In Quepos, Costa Rica, September presents a blend of warmth and moisture, characterized by a maximum temperature reaching 28°C (83°F) and an average of 25°C (77°F). The month is notably wet, with a staggering 931 mm (36.7 in) of rainfall spread over 30 days, fostering a lush, vibrant landscape. Humidity levels soar to an average of 81%, creating a tropical atmosphere that envelops residents and visitors alike. This dynamic weather offers a unique experience for those exploring the rich biodiversity and stunning scenery that Quepos has to offer during this tranquil, albeit rainy, season.

September Temperature in Quepos

In September, the coastal town of Quepos, Costa Rica experiences comfortable temperatures, characterized by a minimum of 22°C (72°F) and a maximum of 28°C (83°F). The consistent average of 25°C (77°F) offers a pleasant climate, making it an appealing destination for those seeking both relaxation and adventure. This month reflects a trend in the region where the temperatures remain fairly stable, transitioning smoothly from the warmer months of May through August, while still providing respite from the heat. With humidity levels rising, September is also part of the rainy season, but the warm temperatures ensure that the lush surroundings remain vibrant and inviting, perfect for exploring the rich biodiversity of this beautiful area.

September Weather in Quepos: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Quepos, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Quepos, September typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec777878787777777777767676
Data source: Temperature data for Quepos generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Quepos

September in Quepos, Costa Rica, marks a peak in the rainy season, delivering an impressive 931 mm (36.7 inches) of precipitation over 30 days. This volume not only contributes to the lush, vibrant landscapes the region is known for but also continues the trend of escalating rainfall from previous months like August, which recorded 914 mm (36.0 inches). The wettest months are typically clustered around the middle of the year, with the rainfall intensity peaking during September and October. As the rain nourishes the dense tropical foliage, visitors can expect to witness the region's stunning biodiversity in full bloom, making it a unique and enchanting time to explore this beautiful coastal paradise.

September Precipitation Trends in Quepos

The chart displays monthly precipitation patterns in Quepos, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Quepos, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec191102107320820696825914931967822456
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Quepos

In September, Quepos, Costa Rica experiences a significant humidity level of 81%, reflecting the region's tropical climate. As the rainy season unfolds, the humidity peaks from June to August, reaching a high of 85% in July. Following this, September maintains a notably elevated humidity, just slightly lower than the preceding months. This trend of high humidity is a stark contrast to the drier beginning of the year, where levels hovered in the mid to high 60s. The transition into October marks a gradual decrease to 80%, yet the overall pattern underscores Quepos’ lush, vibrant environment sustained by its moisture-rich atmosphere.

September Average Humidity in Quepos

This chart illustrates the average monthly humidity levels in Quepos, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Quepos is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec68%68%66%67%69%84%85%82%81%80%80%73%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Quepos

In September, Quepos, Costa Rica, continues to experience an extreme UV Index, maintaining a significant level of 13, similar to August figures. This consistency emphasizes the region's persistent exposure, which requires vigilance when enjoying the sunny weather, as a mere 10 minutes of unprotected sun exposure can lead to skin damage. As the rainy season progresses, the UV Index remains impressively high, ensuring that outdoor enthusiasts must stay protected throughout the month. For more details on UV levels throughout the year, visit Quepos UV Index.

Maximum UV Index Levels in Quepos for September

The chart shows the monthly maximum UV Index (UVI) for Quepos in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Quepos typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec111314141514141313131110
Data source: Quepos September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

September Sunshine in Quepos

September in Quepos, Costa Rica, brings a welcome reprieve from the summer's dappled sunshine with 201 hours of sunlight, reflecting a gentle easing from the peak summer months. This month marks a transition, as the hours of daylight begin to decrease compared to the sun-drenched heights of January through March, which offer over 300 hours each. Though September sees less sun than earlier in the year, it still shines brighter than the latter rainy months, allowing for vibrant exploration amid verdant landscapes. As the year nears its close, one can’t help but appreciate the balance of sun and rain that cultivates the lush beauty Costa Rica is renowned for, making September a perfect time to experience both the warmth of the sun and the richness of nature.

Monthly Sunshine Duration in Quepos: September Highlighted

The September sunshine duration represents the total number of hours Quepos experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec254h298h330h294h221h214h204h194h201h187h228h297h
Data source: Quepos September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Quepos During September

When considering the likelihood of sunny weather in Quepos, Costa Rica, September stands out with a mere 7% chance of sunshine, making it one of the least favorable months for sun-seekers. This trend of limited sunlight is consistent throughout the rainy season, as evidenced by the subdued percentages from June to August, where the chances drop significantly to 4% in August and only 9% in June. Fortunately, the weather improves as the year progresses, with sun chances gradually rising again in October and November. For those planning a visit in September, it's wise to expect overcast skies and plan for potential rain rather than relying on bright sunshine.

Percentage of Sunny Days in September in Quepos

The chart illustrates the percentage of sunny days in Quepos throughout the year, with September highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Quepos experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec38%41%48%17%10%9%11%4%7%11%14%30%
Data source: Quepos September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Quepos in September

In September, visitors to Quepos, Costa Rica can expect a delightful 12 hours of daylight each day, marking a consistent trend that begins in March and holds steady through this vibrant month. As the rainy season peaks, the extended daylight offers opportunities for both adventure and relaxation. Following the lush green landscapes, the region's flora is particularly vivid during this time, making the longer days ideal for exploring the natural beauty of coastal trails and wildlife. This shift in daylight hours reflects a broader pattern where longer, sunlit days prevail from early spring to late summer, before gradually tapering off into the shorter daylight of the late fall. Whether you’re soaking up the sun or enjoying the cooler evening air, September in Quepos offers perfect conditions to embrace the day's light.

Average Daylight Hours in Quepos for September

The chart illustrates the variation in daylight duration in Quepos throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec11h 37m11h 48m12h 3m12h 19m12h 33m12h 39m12h 35m12h 24m12h 9m11h 53m11h 40m11h 33m
Data source: Quepos daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Quepos

In September, the winds in Quepos, Costa Rica tend to be slightly gentler, with an average speed of 1.3 m/s (3 mph), marking the end of the dry season's breezy charm. This subtle drop in wind speed, transitioning from the more robust conditions of August, reflects a transitional phase in the region's climate. Overall, the wind speeds throughout the year remain fairly stable, hovering around the 1.4 m/s (3 mph) mark, with only minor fluctuations. Notably, November brings a slight increase back to 1.5 m/s (3 mph), suggesting a shift toward the upcoming wet season. As the winds gracefully dance through September, they paint a tranquil picture of life in this vibrant coastal enclave, where the air is infused with the promise of lush greenery and renewal.

Average September Wind Speed in Quepos

The chart displays monthly wind speed patterns in Quepos, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec1.41.41.41.41.41.41.41.51.3 m/s1.41.51.3
Data source: Quepos September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Quepos Compares to Other Months

Weather in Quepos varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Quepos, focusing on differences in temperature, rainfall, humidity, and UV levels.

In comparing the weather of September and January, it's clear that both months experience similar temperature ranges, with minimums around 21-22°C (71-72°F), averages at 25°C (77°F), and maximums peaking at 28°C (83°F). However, September significantly stands out with a much higher precipitation level of 931 mm (36.7 in) over 30 days, compared to January's 191 mm (7.5 in) over 22 days. Additionally, the humidity in September is notably higher at 81%, while January enjoys a more comfortable 68%. For a detailed look at January weather patterns, you can check out Quepos weather in January.

When comparing the weather in September and February, we see notable differences in temperature and precipitation. September typically experiences warmer temperatures, with an average of 25°C (77°F) and maximums reaching up to 28°C (83°F), while February's temperatures are quite similar but slightly cooler, with maximums peaking at 29°C (84°F). However, September is characterized by significantly higher rainfall, with a staggering 931 mm (36.7 in) over 30 days, compared to February's much drier 102 mm (4.0 in) over just 21 days. Additionally, humidity levels in September are higher at 81%, while in February, they drop to 68%, making February a more comfortable month overall. For more detailed information on the weather, you can check Quepos weather in February.

When comparing the weather in September and March, a few notable differences stand out. September tends to be more humid, with an average humidity of 81%, while March experiences a lower humidity level of 66%. The temperatures are quite similar, with September's average at 25°C (77°F) compared to March's average of 26°C (79°F), but September sees significantly more rainfall, with 931 mm (36.7 in) over 30 days, contrasted with March's 107 mm (4.2 in) over just 24 days. For those interested in specific weather details for March, you can check out Quepos weather in March.

In September, the weather is characterized by warm temperatures, with a minimum of 22°C (72°F), an average of 25°C (77°F), and a maximum of 28°C (83°F). However, this month experiences significantly higher precipitation, totaling 931 mm (36.7 in) over 30 days, coupled with high humidity levels at 81%. In contrast, April presents a slightly warmer average temperature of 26°C (78°F) with maximums reaching 29°C (84°F), while the overall precipitation is much lower at 320 mm (12.6 in) across 29 days, resulting in a more comfortable humidity level of 67%. For more detailed information on April weather, check out Quepos weather in April.

When comparing the weather in September and May, both months exhibit warm temperatures, with averages around 25°C (77°F). However, September tends to feel more humid, with humidity levels at 81%, compared to May’s drier 69%. In terms of precipitation, September receives more rainfall, totaling 931 mm (36.7 in) over 30 days, while May sees 820 mm (32.3 in) across 31 days. This can make September feel wetter and more tropical. For more detailed information, you can check out Quepos weather in May.

In comparing the weather between September and June, both months exhibit similar temperature patterns, with minimum temperatures around 22°C (72°F) and average temperatures hovering near 25°C (77°F to 78°F). However, June tends to be slightly warmer with a maximum temperature of 29°C (84°F), compared to September's maximum of 28°C (83°F). Notably, September experiences significantly higher rainfall, totaling 931 mm (36.7 in), in contrast to June's 696 mm (27.4 in), making September the wetter month. The humidity remains consistently high in both months, with September at 81% and June at 84%. For more details on June weather, check out Quepos weather in June.

In comparing the weather between September and July, both months exhibit similar temperature ranges, with minimums around 22°C (72-73°F) and average temperatures typically sitting at 25°C (77°F). However, July tends to be slightly warmer with a maximum temperature of 29°C (84°F), whereas September peaks at 28°C (83°F). Precipitation is notably heavier in September, with 931 mm (36.7 in) recorded over the month, compared to July's 825 mm (32.5 in). Additionally, September sees a similar number of rainy days, though it slightly trails July's total of 31 days. Humidity is also marginally lower in September at 81%, compared to 85% in July. For more details on July weather specifics, you can refer to the following link: Quepos weather in July.

In comparing the weather between September and August, we notice that both months share similar temperatures, with minimums of 22°C (72°F), averages of 25°C (77°F), and maximums of 28°C (83°F). However, September sees a slight increase in precipitation, measuring 931 mm (36.7 in) over 30 days, compared to August's 914 mm (36.0 in) over 31 days. Humidity levels remain fairly consistent, with September at 81% and August slightly higher at 82%. For more detailed information on August weather, you can check Quepos weather in August.

In comparing the weather between September and October, both months exhibit similar temperature ranges, with minimums around 22°C (72°F), averages at 25°C (77°F), and maximums reaching 28°C (83°F). However, October sees a slight increase in precipitation, totaling 967 mm (38.1 in) compared to September's 931 mm (36.7 in), contributing to an overall wetter month. Humidity levels remain comparable, hovering around 81% in September and slightly decreasing to 80% in October. For more detailed information on the weather during this month, you can visit Quepos weather in October.

In September, the weather features minimum temperatures around 22°C (72°F), with an average of 25°C (77°F) and maximums reaching 28°C (83°F). The month is characterized by high humidity at 81% and significant precipitation, totaling 931 mm (36.7 in) over 30 days. Conversely, November shares similar temperature ranges, with a minimum of 22°C (71°F), an average of 25°C (76°F), and a maximum of 28°C (83°F). However, November experiences slightly lower precipitation at 822 mm (32.4 in) while maintaining similar humidity levels of 80%. For more detailed information, you can refer to Quepos weather in November.

In comparing the weather between September and December, we see that both months maintain a similar average temperature of around 25°C (77°F), with maximums peaking at 28°C (82°F) in December and 28°C (83°F) in September. However, September is notably wetter, experiencing 931 mm (36.7 in) of precipitation across 30 days compared to December's 456 mm (18.0 in). Additionally, humidity levels are higher in September at 81%, while December enjoys a slightly drier atmosphere with 72% humidity. For more specific details about December weather in Quepos, visit Quepos weather in December.

Compare Quepos's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Quepos

September in Quepos is characterized by its deluge, as the region experiences its wettest month of the year. With consistent rainfall almost every day, the lush landscape thrives, giving the area a vibrant green hue. Though temperatures remain mild and inviting, with averages hovering around 25°C (77°F), the humidity rises, creating a tropical atmosphere. This month starkly contrasts with the drier season, turning Quepos into a serene sanctuary for those seeking to enjoy nature's beauty in full bloom. For a deeper understanding of how these conditions fit within the yearly cycle, explore the Quepos Climate.