September Weather in Puntarenas, Costa Rica

Last updated: August 21, 2025

In Puntarenas, Costa Rica, September brings a warm embrace with maximum temperatures reaching 30°C (86°F) and an average temperature of 25°C (77°F). However, the month is characterized by significant precipitation, totaling 422 mm (16.6 in), with rain likely on nearly all 30 days. High humidity levels at 81% add to the tropical ambiance, creating a lush and vibrant environment. Visitors should prepare for daily showers, which contribute to the region's rich natural beauty and encourage the flourishing of its diverse ecosystems.

September Temperature in Puntarenas

September in Puntarenas, Costa Rica heralds a subtle shift in the climate, characterized by warm tropical temperatures that provide a comforting backdrop for visitors. With a minimum of 22°C (72°F) and reaching a pleasant maximum of 30°C (86°F), the month maintains an average of around 25°C (77°F), creating an inviting atmosphere. Following the slightly warmer months of July and August, September sees a slight dip in temperatures, offering a refreshing respite. While the weather remains predominantly warm, the consistent monthly averages indicate a tropical climate that oscillates modestly, making it an ideal time to explore the natural beauty and rich biodiversity this stunning region has to offer.

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

The chart illustrates September temperature patterns in Puntarenas, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Puntarenas, 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).
JanFebMarAprMayJunJulAugSepOctNovDec788080797878787877777777
Data source: Temperature data for Puntarenas 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 Puntarenas

September in Puntarenas, Costa Rica, marks the culmination of a notably wet season, as the region experiences a significant precipitation total of 422 mm (16.6 in) over approximately 30 rainy days. This month echoes the patterns established in the preceding months, where rainfall has been abundant, peaking in May and June with over 400 mm each. The consistent downpours throughout the wet season not only sustain the lush tropical landscapes but also enhance the vibrancy of local ecosystems. As September transitions into October, residents and visitors alike brace for even more intense rainfall, with October historically showcasing the highest precipitation levels of the year at 643 mm (25.3 in). The rhythmic cycle of heavy rains reinforces Puntarenas’ identity as a lush paradise, deeply intertwined with the tropical climate's dynamic nature.

September Precipitation Trends in Puntarenas

The chart displays monthly precipitation patterns in Puntarenas, 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 Puntarenas, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec29142014742442136542142264327689
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Puntarenas

In September, Puntarenas experiences a humidity level of 81%, which is a slight decrease from the peaks of June and July at 84% and 85%, respectively. This month falls within the rainy season, contributing to a consistently humid atmosphere that is characteristic of the region. Transitioning from the higher humidity months, September still maintains elevated moisture levels, paving the way for the more moderate conditions of October at 80% and November at 80%. The data indicates a pattern of elevated humidity during the summer months, gradually tapering off as the year approaches its end, highlighting the tropical qualities of this beautiful coastal locale.

September Average Humidity in Puntarenas

This chart illustrates the average monthly humidity levels in Puntarenas, 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 Puntarenas 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 Puntarenas

In September, Puntarenas, Costa Rica, continues to experience an extreme UV Index of 13, matching the values of the preceding two months. This consistency indicates a sustained risk for skin damage within just 10 minutes of sun exposure, so sun protection remains crucial. With temperatures and UV levels consistently high throughout the dry season from January to August, this trend does not show signs of abating in September. As the month progresses toward October, the UV Index holds steady at 13, suggesting that careful planning is essential for outdoor activities. For comprehensive insights on sun safety, visit the detailed Puntarenas UV Index.

Maximum UV Index Levels in Puntarenas for September

The chart shows the monthly maximum UV Index (UVI) for Puntarenas 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 Puntarenas typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec111314141414131313131110
Data source: Puntarenas 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 Puntarenas

September in Puntarenas, Costa Rica, welcomes visitors with a gentle glow of sunshine, offering an average of 251 hours of sunlight. This month serves as a delightful bridge between the brighter, more vibrant months of March and April, which boast over 300 hours of sun, and the slightly cloudier days that follow in October. While September sees a modest dip compared to the peak summer months, it still maintains a warm embrace, making it an inviting time for travelers seeking a blend of sunny days amid the lush, green backdrop that comes alive during the rainy season. As the year progresses, September stands out for its balance, ensuring that visitors can enjoy both the beauty of nature and the comfort of the sun's rays before the clouds begin to take over.

Monthly Sunshine Duration in Puntarenas: September Highlighted

The September sunshine duration represents the total number of hours Puntarenas 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.
JanFebMarAprMayJunJulAugSepOctNovDec257h299h332h314h261h260h267h247h251h231h272h311h
Data source: Puntarenas September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Puntarenas During September

As September rolls into Puntarenas, Costa Rica, the likelihood of sunny weather takes a significant dip, with only an 11% chance of clear skies. This marks one of the lowest probabilities of sun throughout the year, following a trend of declining sunshine from the sunny first half of the year—where January and February boast chances above 59%—to the particularly damp months of late summer. As the region transitions from the dry season into the height of the rainy period, visitors should brace for overcast days and frequent showers, making them all the more precious.

Percentage of Sunny Days in September in Puntarenas

The chart illustrates the percentage of sunny days in Puntarenas 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 Puntarenas experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec59%61%58%28%20%16%20%7%12%17%34%59%
Data source: Puntarenas September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Puntarenas in September

In September, Puntarenas, Costa Rica, enjoys a consistent 12 hours of daylight, continuing the trend observed since March. This month, like its predecessors from April to August, showcases the region's remarkable stability in daylight duration, making it a perfect time for outdoor activities and exploration. As the year transitions into October, daylight will gradually decrease to 11 hours, marking a shift towards shorter days as the rainy season progresses. This predictable pattern reflects the natural rhythms of the tropics, creating an inviting atmosphere for both locals and visitors eager to bask in the golden sunshine.

Average Daylight Hours in Puntarenas for September

The chart illustrates the variation in daylight duration in Puntarenas throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec11h 36m11h 47m12h 3m12h 20m12h 34m12h 41m12h 37m12h 25m12h 9m11h 52m11h 39m11h 32m
Data source: Puntarenas daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Puntarenas

As September unfolds in Puntarenas, Costa Rica, the wind whispers a gentle tune, with an average speed dipping to 1.4 m/s (3 mph). This soft breeze reflects a gradual decline from the slightly stronger winds of earlier months, peaking in March with 2.1 m/s (5 mph). Following the lively energy of the dry season, the winds settle, mirroring the transition from the vibrant summer months to the more tranquil rainy season. Visitors can expect a serene atmosphere, perfect for leisurely strolls along the coast, as the September winds create a delicate balance, enveloping the region in a calming embrace.

Average September Wind Speed in Puntarenas

The chart displays monthly wind speed patterns in Puntarenas, 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.
JanFebMarAprMayJunJulAugSepOctNovDec1.92.02.11.71.61.51.51.51.4 m/s1.41.51.6
Data source: Puntarenas September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Puntarenas Compares to Other Months

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

In September, the weather is characterized by warmer temperatures, with a minimum of 22°C (72°F) and an average of 25°C (77°F), reaching a maximum of 30°C (86°F). This month experiences significant rainfall, totaling 422 mm (16.6 in) over 30 days, contributing to high humidity levels at 81%. In contrast, January offers a slightly cooler climate, with temperatures ranging from a minimum of 20°C (69°F) to a maximum of 32°C (90°F) and an average of 26°C (78°F). The precipitation is vastly lower, at just 29 mm (1.1 in) across 8 days, resulting in a drier atmosphere with humidity levels around 68%. For more detailed information on the weather conditions in January, you can explore Puntarenas weather in January.

September and February exhibit notable differences in weather patterns. In September, temperatures range from a minimum of 22°C (72°F) to a maximum of 30°C (86°F), with an average of 25°C (77°F). This month experiences high humidity at 81% and significant rainfall, totaling 422 mm (16.6 in) over 30 days. In contrast, February offers slightly lower minimum temperatures at 20°C (68°F) and a higher maximum of 33°C (92°F), with an average of 26°C (80°F). The humidity drops to 68%, and precipitation is minimal, with just 14 mm (0.5 in) over 4 days. For more specific details, you can check Puntarenas weather in February.

September and March offer contrasting weather conditions in terms of temperature, precipitation, and humidity. September typically experiences a warmer and more humid climate, with average temperatures around 25°C (77°F) and a significant amount of rainfall at 422 mm (16.6 in) over 30 days, resulting in a humidity level of 81%. In contrast, March boasts slightly cooler average temperatures of 27°C (81°F), with maximums reaching up to 34°C (93°F), but remarkably low precipitation at just 20 mm (0.8 in) over 5 days and a lower humidity of 66%. This makes March a much drier and sunnier month compared to the often rainy September. For more detailed weather insights, check Puntarenas weather in March.

When comparing the weather in September and April, September tends to be slightly cooler with average temperatures ranging from a minimum of 22°C (72°F) to a maximum of 30°C (86°F). However, it is also marked by significantly higher humidity at 81% and more precipitation, totaling 422 mm (16.6 in) over 30 days. In contrast, April features a warmer average temperature, with a minimum of 21°C (71°F) and reaching up to 33°C (91°F), while experiencing relatively lower humidity at 67% and considerably less rainfall, accumulating 147 mm (5.8 in) over just 25 days. For more detailed information on April weather, you can check Puntarenas weather in April.

When comparing the weather in September and May, we observe some notable similarities and differences. Both months feature a minimum temperature of around 22°C (72°F), but May tends to be slightly warmer on average, with temperatures reaching up to 31°C (88°F) compared to September's maximum of 30°C (86°F). Precipitation levels are quite similar, with September receiving 422 mm (16.6 in) over 30 days and May experiencing slightly higher rainfall at 424 mm (16.7 in) over 31 days. However, the humidity in September is higher at 81%, while in May, it is relatively lower at 69%. For more detailed information, you can check out Puntarenas weather in May.

In comparing the weather between September and June, both months exhibit similar temperature ranges, with September showing a minimum of 22°C (72°F), an average of 25°C (77°F), and a maximum of 30°C (86°F). In contrast, June features a slightly higher average temperature of 26°C (78°F) and a maximum of 31°C (87°F). Precipitation levels are comparable as well, with September receiving 422 mm (16.6 in) and June reporting 421 mm (16.6 in), both distributed over 30 days. However, September has a humidity level of 81%, while June is slightly more humid at 84%. For more details specifically about June weather, you can refer to Puntarenas weather in June.

In comparing the weather of September and July, both months share a warm climate, but with some notable differences. September tends to be slightly cooler, with an average temperature of 25°C (77°F) compared to July's average of 26°C (78°F). Additionally, while July experiences a maximum temperature of 31°C (87°F), September's peak reaches 30°C (86°F). Precipitation also differs, as September sees more rainfall at 422 mm (16.6 in) compared to July's 365 mm (14.4 in), indicating that September is generally wetter. Humidity levels are fairly high in both months, with September at 81% and July at 85%. For more detailed information, you can check Puntarenas weather in July.

In comparing the weather patterns of September and August, we find that both months exhibit similar temperature ranges, with minimums around 22°C (72°F), average temperatures of approximately 25°C (77°F), and maximums reaching 30°C (86°F in September and 87°F in August). Precipitation levels are also closely aligned, with September receiving 422 mm (16.6 in) over 30 days and August slightly less at 421 mm (16.6 in) across 31 days. Humidity remains high in both months, with September at 81% and August at 82%. For more detailed insights, you can refer to Puntarenas weather in August.

September and October in Puntarenas present subtly different weather patterns, despite their comparable temperatures. Both months maintain a minimum of 22°C (72°F) and an average of 25°C (77°F), but October sees a slight decrease in maximum temperatures, peaking at 29°C (85°F) compared to September's 30°C (86°F). Rainfall also escalates in October, with 643 mm (25.3 in) of precipitation, significantly higher than September's 422 mm (16.6 in). The humidity remains fairly consistent, at 81% in September and 80% in October, creating a similar feel to both months. For more details about October's weather specifically, you can check Puntarenas weather in October.

In comparing September and November weather, we see that both months typically share similar temperature ranges, with September featuring a minimum of 22°C (72°F) and November slightly cooler at 21°C (71°F). Both months have an average temperature of 25°C (77°F) and can reach a maximum of 30°C (86°F). However, September is characterized by significantly higher precipitation, with 422 mm (16.6 in) spread over 30 days, while November sees a more moderate rainfall of 275 mm (10.8 in) over 29 days. Humidity levels are also quite similar, with September at 81% and November at 80%. For more detailed insights into the weather patterns in November, you may refer to Puntarenas weather in November.

In September, the weather is characterized by warm temperatures, with lows around 22°C (72°F), an average of 25°C (77°F), and highs reaching 30°C (86°F). The month experiences significant rainfall, totaling 422 mm (16.6 in), spread over 30 days, contributing to high humidity levels at 81%.

In contrast, December offers a slightly warmer feel with minimum temperatures of 21°C (70°F) and an average of 25°C (78°F), peaking at 31°C (89°F). Precipitation drops considerably to 89 mm (3.5 in) across 20 days, resulting in reduced humidity at 72%. This shift creates a more pleasant and drier environment compared to September. For more detailed information on December weather, visit Puntarenas weather in December.

Compare Puntarenas's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Puntarenas

In September, Puntarenas experiences a distinctive tropical climate, marked by high humidity levels averaging around 81% and significant rainfall, totaling 422 mm over the month. This contrasts sharply with other months where precipitation is generally lower and the skies may be clearer. The temperatures remain relatively warm, with an average of 25°C, providing a consistent tropical feel. However, the month stands out for its daily rain showers, often making it a more challenging time for outdoor activities. For those curious about the nuances of Puntarenas' climate, further details can be found at Puntarenas Climate.