September Weather in Santa Cruz, Costa Rica

Last updated: August 21, 2025

September in Santa Cruz, Costa Rica presents a tropical climate characterized by warm temperatures and high humidity. With maximum temperatures reaching 34°C (93°F) and an average of 26°C (79°F), the weather remains inviting despite the rain. This month experiences significant precipitation, accumulating around 353 mm (13.9 in) over 28 days, leading to a lush and vibrant landscape. Travelers can expect humidity levels around 80%, creating a lush environment that emphasizes the region's natural beauty, making September a unique time to explore the rich biodiversity of Costa Rica.

September Temperature in Santa Cruz

In September, Santa Cruz, Costa Rica, embraces a warm tropical climate, with temperatures ranging from a mild minimum of 22°C (71°F) to a comfortable maximum of 34°C (93°F). The average temperature hovers around 26°C (79°F), reflecting a slight drop compared to the summer months, yet still offering plenty of warmth for outdoor adventures. As the rain showers increase during this time, the landscape flourishes, creating a vibrant backdrop for exploring the region. Overall, September presents an inviting blend of warm temperatures and refreshing rain, making it a unique time to experience the beauty of Costa Rica.

September Weather in Santa Cruz: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Santa Cruz, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Santa Cruz, 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).
JanFebMarAprMayJunJulAugSepOctNovDec818283848280807979787980
Data source: Temperature data for Santa Cruz generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Santa Cruz

In September, Santa Cruz, Costa Rica, experiences a significant uptick in precipitation, recording 353 mm (13.9 in) of rain over 28 days. This makes it one of the wettest months of the year, closely following the even rainier October. The trend is clear: as the year progresses into the latter half, rainfall becomes increasingly frequent and intense. This is particularly evident when comparing September's downpour to the dryer months earlier in the year, such as February, which sees almost no rain. Travelers should be prepared for the lush, vibrant landscapes that the September rains foster, but also for the frequent showers that contribute to them.

September Precipitation Trends in Santa Cruz

The chart displays monthly precipitation patterns in Santa Cruz, 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 Santa Cruz, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec12245228635921529035340713031
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Santa Cruz

September in Santa Cruz, Costa Rica, typically showcases moderate to high humidity, averaging around 80%. This places it just slightly below the peak levels seen in the preceding months of July and August, which reach a humidity of 85% and 82%, respectively. Following the intensifying humidity of the mid-year, September signals a gradual shift as the wet season progresses, leading to more comfortable conditions. The humidity levels during this month, while considerable, are part of a downward trend that continues into October and November, suggesting a subtle tapering off as the year transitions toward the drier months. Overall, September remains a sticky but enchanting time in Santa Cruz, where the lush landscapes thrive under the ample moisture.

September Average Humidity in Santa Cruz

This chart illustrates the average monthly humidity levels in Santa Cruz, 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 Santa Cruz is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec66%64%63%63%63%74%85%82%80%79%79%70%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Santa Cruz

In September, Santa Cruz, Costa Rica, maintains its reputation for high UV exposure, with a UV Index of 13, categorizing it as extreme. This sustained level, consistent with the previous month and in line with the year’s trend of predominantly extreme UV ratings, means that even short periods outdoors can lead to sunburn in just 10 minutes. As summer transitions into fall, visitors and locals alike should remain vigilant about sun protection, mirroring the year's earlier months where indices climbed as high as 14 in mid-year. For those exploring this vibrant region, staying informed is crucial; check detailed reports at Santa Cruz UV Index.

Maximum UV Index Levels in Santa Cruz for September

The chart shows the monthly maximum UV Index (UVI) for Santa Cruz 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 Santa Cruz typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec111314141414141313131110
Data source: Santa Cruz 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 Santa Cruz

As September rolls into Santa Cruz, Costa Rica, sunshine hours begin to wane slightly, with 268 hours of golden rays lighting up the month. This decline follows a vibrant summer, highlighted by the peak of 334 hours in March and a hearty 312 hours in July, painting a picture of sunny splendor. Even though September sees fewer sunny days than its predecessors, it still outshines the upcoming October, which is forecasted to glow with just 245 hours. The gentle transition into fall showcases a steady rhythm of sunshine that ebbs and flows, providing a warm embrace before the cooler months take hold.

Monthly Sunshine Duration in Santa Cruz: September Highlighted

The September sunshine duration represents the total number of hours Santa Cruz 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.
JanFebMarAprMayJunJulAugSepOctNovDec261h300h334h324h278h282h312h278h268h245h296h322h
Data source: Santa Cruz September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Santa Cruz During September

September in Santa Cruz, Costa Rica, sees a notable dip in sunny weather, with a mere 13% chance of clear skies. This trend marks one of the lowest probabilities of sunshine for the year, following the already overcast months of August and July, which also struggle to bring bright days. As the lush landscapes flourish under a heavy blanket of rain, travelers might find September less appealing for sun-seeking adventures. The month acts as a transition towards the brighter days of October and November, which gradually improve to 19% and 41% respectively, hinting at a welcome return of sunny weather as the rainy season starts to wane.

Percentage of Sunny Days in September in Santa Cruz

The chart illustrates the percentage of sunny days in Santa Cruz 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 Santa Cruz experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec60%67%58%30%26%20%24%7%13%19%41%72%
Data source: Santa Cruz September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Santa Cruz in September

In Santa Cruz, Costa Rica, the trend of daylight duration showcases a remarkable consistency throughout the year. From January to August, residents enjoy a steady 12 hours of daylight, creating an inviting atmosphere perfect for outdoor activities and exploration. As September unfolds, this pattern continues, with daylight remaining at 12 hours, ensuring that the vibrant energy of the region persists. As the year transitions into October, daylight begins to taper off slightly to 11 hours, hinting at the onset of the rainy season. This gradual shift underscores the subtropical climate's influence on daily life, offering a balance between abundant sunny days and the refreshing rains of the approaching months.

Average Daylight Hours in Santa Cruz for September

The chart illustrates the variation in daylight duration in Santa Cruz throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec11h 35m11h 47m12h 3m12h 20m12h 35m12h 42m12h 38m12h 25m12h 9m11h 52m11h 38m11h 31m
Data source: Santa Cruz daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Santa Cruz

As September settles in Santa Cruz, Costa Rica, the wind takes on a gentle demeanor, with average speeds dropping to 1.3 m/s (about 3 mph). This represents a part of the gradual decline in wind intensity that begins mid-year, after experiencing slightly higher speeds earlier in the spring months. In fact, April and May boast breezier conditions, with winds reaching up to 2.5 m/s (5 mph) and 2.2 m/s (5 mph), before tapering off considerably during the summer months. By the time September arrives, the serene and mild winds create a tranquil atmosphere, setting the stage for the lush greenery that thrives in this tropical paradise. As the year progresses, one can anticipate a slight uptick in wind speed again come November, hinting at the cyclical nature of this beautiful coastal environment.

Average September Wind Speed in Santa Cruz

The chart displays monthly wind speed patterns in Santa Cruz, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.53.64.02.52.21.52.01.41.3 m/s1.22.32.8
Data source: Santa Cruz September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Santa Cruz Compares to Other Months

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

In September, the weather is characterized by warmer temperatures and higher humidity, with average highs reaching 34°C (93°F) and considerable precipitation of 353 mm (13.9 in) spread across 28 days. This creates a lush, tropical atmosphere, but also makes the month feel quite damp, with humidity levels around 80%. In contrast, January brings slightly cooler temperatures, with minimums of 17°C (64°F) and maximums reaching 36°C (97°F), but enjoys a much drier climate with only 12 mm (0.5 in) of rain over just 2 days. The humidity also drops to 66%, providing a more comfortable and pleasant experience for outdoor activities. For more details on January weather, visit Santa Cruz weather in January.

September and February exhibit striking differences in weather conditions. September experiences significantly higher humidity at 80% and a notable amount of rainfall, with precipitation reaching 353 mm over 28 days, making it a relatively wet month. In contrast, February enjoys a drier climate, characterized by just 2 mm of rain over 0 days, and lower humidity at 64%. Temperature ranges also vary, with September averaging 26°C (79°F) and peaking at 34°C (93°F), while February offers warmer averages at 28°C (82°F) and higher maximums of 37°C (99°F). For more details on February weather specifically, you can check out Santa Cruz weather in February.

In September, the weather is characterized by higher humidity and significant rainfall, with temperatures ranging from a minimum of 22°C (71°F) to a maximum of 34°C (93°F) and an average of 26°C (79°F). The month experiences about 353 mm (13.9 in) of precipitation spread over 28 days, resulting in a consistently damp environment. In contrast, March boasts warmer temperatures, with a minimum of 20°C (69°F) and reaching up to 37°C (99°F), averaging 28°C (83°F), but it is remarkably dry with only 4 mm (0.1 in) of precipitation over 0 days, contributing to a more comfortable humidity level of 63%. For more details, check out Santa Cruz weather in March. Overall, March offers a stark contrast to September’s wet and humid conditions.

September and April present contrasting weather profiles. 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). Rainfall is significant during this month, with 353 mm (13.9 in) of precipitation over 28 days, contributing to a high humidity level of 80%. In contrast, April experiences warmer temperatures, featuring a minimum of 22°C (71°F), an average of 29°C (84°F), and a peak of 39°C (102°F). Notably, April is much drier, with only 51 mm (2.0 in) of rain recorded over 9 days, leading to a lower humidity level of 63%. For more details on April weather, visit Santa Cruz weather in April.

When comparing the weather in September and May, several notable differences emerge. September tends to be slightly cooler, with average temperatures ranging from a minimum of 22°C (71°F) to a maximum of 34°C (93°F). In contrast, May is warmer, featuring temperatures that start at a minimum of 23°C (73°F) and can reach as high as 38°C (101°F). Additionally, September experiences more precipitation, with 353 mm (13.9 in) of rain over 28 days, compared to May's 286 mm (11.2 in) over 22 days. Humidity is also significantly higher in September at 80%, while May has a more comfortable level at 63%. For more information, you can check out Santa Cruz weather in May.

When comparing the weather in September and June, both months share similar minimum temperatures, averaging around 22°C (72°F). However, June tends to be slightly warmer overall, with an average temperature of 27°C (80°F) compared to September's 26°C (79°F). In terms of maximum temperatures, June peaks at a sweltering 36°C (97°F), whereas September reaches a maximum of 34°C (93°F). Both months experience significant rainfall, with September receiving 353 mm (13.9 in) over 28 days and June slightly higher at 359 mm (14.1 in) over 26 days. Additionally, June has a lower humidity level of 74%, compared to September's more humid 80%. For a detailed look at June's weather, check out Santa Cruz weather in June.

In comparing the weather between September and July, September typically experiences slightly higher humidity at 80% compared to July's 85%. The average temperature in September is around 26°C (79°F), which is similar to July's average of 27°C (80°F), while the maximum temperature in September reaches 34°C (93°F) compared to July’s peak of 35°C (95°F). However, September sees significantly more rainfall, with 353 mm (13.9 in) over 28 days, in contrast to July's 215 mm (8.4 in) across 23 days. For more detailed information, visit Santa Cruz weather in July.

In comparing the weather patterns of August and September, we see that both months exhibit similar temperature ranges, with minimums around 22°C (71°F) and average temperatures of approximately 26°C (79°F). However, September tends to be slightly cooler at the higher end, with a maximum of 34°C (93°F) compared to August's peak of 35°C (95°F). Notably, September is characterized by significantly higher precipitation, totaling 353 mm (13.9 in) over 28 days, which exceeds August's 290 mm (11.4 in) over 25 days. Both months experience high humidity levels, though September is marginally lower at 80% compared to August's 82%. For a detailed look at the weather specifics for August, you can check Santa Cruz weather in August.

In comparing the weather between September and October, both months maintain a warm average temperature of around 26°C (79°F), with September slightly warmer at a maximum of 34°C (93°F) compared to October's 33°C (92°F). However, October experiences an increase in precipitation, totaling 407 mm (16.0 in) over 29 days, while September receives 353 mm (13.9 in) across 28 days. Humidity levels remain similar, with September slightly higher at 80% compared to October's 79%. For more detailed insights into October's weather, you can check Santa Cruz weather in October.

In September, the weather is noticeably warmer with minimum temperatures around 22°C (71°F) and maximums reaching up to 34°C (93°F), while November sees slightly cooler temperatures, with minimums of 20°C (68°F) and maximums peaking at 33°C (93°F). Both months have an average temperature of 26°C (79°F), but September experiences significantly more rainfall, totaling 353 mm (13.9 in) over 28 days compared to November's 130 mm (5.1 in) across just 15 days. Humidity levels remain high in both months, with September at 80% and November slightly lower at 79%. For more detailed information, you can check Santa Cruz weather in November.

September and December weather exhibit notable differences in temperature, precipitation, and humidity. 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). The month is characterized by heavy rainfall, totaling 353 mm (13.9 in) across 28 days, and high humidity levels at 80%. In contrast, December features slightly milder temperatures, with a minimum of 20°C (69°F) and a maximum of 35°C (95°F), averaging 27°C (80°F). This month is much drier, with only 31 mm (1.2 in) of rain over just 4 days and lower humidity at 70%. For more details on December weather, check out Santa Cruz weather in December.

Compare Santa Cruz's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Santa Cruz

In September, Santa Cruz experiences a unique blend of warm temperatures and significant rainfall, distinguishing it from the rest of the year. With average highs around 26°C and humidity levels soaring to 80%, the atmosphere is both steamy and vibrant. Frequent rain showers mark almost every day, leading to a total precipitation that far surpasses other months. This combination not only creates lush landscapes but also invites a refreshing, tropical ambiance. As the wet season unfolds, September offers a captivating glimpse into the region's natural beauty, making it a time of transformation and renewal. For more detailed insights, visit Santa Cruz Climate.