September Weather in Kourou, French Guiana

Last updated: August 21, 2025

Experience the vibrant September weather of Kourou, French Guiana, where temperatures delight under a tropical sun. Expect maximum highs of 31°C (88°F), with an average temperature of 27°C (81°F), dipping to a pleasant minimum of 24°C (75°F). This month brings about 92 mm (3.6 in) of rainfall spread over 16 days, contributing to a relative humidity of 62% that enhances the lush landscapes. Whether you’re exploring the region’s rich biodiversity or seeking thrilling space launch events, Kourou’s September climate offers a captivating backdrop for any adventure.

September Temperature in Kourou

In September, Kourou, French Guiana, experiences a warm and inviting climate, with temperatures reflecting a consistent tropical pattern. The month sees minimums around 24°C (75°F) and averages reaching 27°C (81°F), while highs peak at about 31°C (88°F). This slight increase in warmth compared to the previous months emphasizes the subtle transition towards the warmer end of the year. The stable temperatures, combined with its tropical setting, make September an excellent time to explore the lush surroundings of Kourou, where the humidity is balanced by the gentle coastal breezes.

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

The chart illustrates September temperature patterns in Kourou, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Kourou, 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).
JanFebMarAprMayJunJulAugSepOctNovDec797979797979798181818079
Data source: Temperature data for Kourou 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 Kourou

September in Kourou, French Guiana, marks a notable dip in precipitation, with just 92 mm (3.6 in) of rainfall recorded over 16 days. This is a significant decrease compared to the preceding months, especially from the heavy downpours of May and June, which often exceed 500 mm. As the dry season approaches, September serves as a transitional period, where the relentless rain of the earlier months gives way to a more tempered climate, hinting at the end of the wet season. This gradual shift not only provides brief respite for the lush vegetation but also prepares the region for the lighter rains that characterize October and November.

September Precipitation Trends in Kourou

The chart displays monthly precipitation patterns in Kourou, 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 Kourou, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec2021721913755414482591159269212322
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Kourou

In September, Kourou experiences a noticeable dip in humidity, averaging at a comfortable 62%. This decline marks the culmination of a generally humid season that peaks in June with a substantial 86%, creating a striking contrast as the months progress. Following the lush and sticky months of summer, September stands out as one of the driest months, which can be refreshing for both residents and visitors. As the year transitions towards the end, humidity begins to creep back up, reaching 63% in October. This trend highlights the tropical climate's fluctuations, where humidity can vary significantly, influencing everything from the environment to daily activities in this vibrant region of French Guiana.

September Average Humidity in Kourou

This chart illustrates the average monthly humidity levels in Kourou, 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 Kourou is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec70%66%66%66%68%86%76%65%62%63%74%79%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Kourou

In September, Kourou, French Guiana, continues to feel the intensity of the sun with a UV Index of 13, placing it firmly in the extreme exposure category. This means that within just 10 minutes, unprotected skin can suffer from sunburn. As the year progresses from January through September, the UV Index remains consistently high, with values often peaking around 16 in March and April. This trend reflects a powerful sun that demands vigilance and proper sun protection, as even the seemingly mild number in September signals the need for caution. For more detailed information about UV levels throughout the year, check out Kourou UV Index.

Maximum UV Index Levels in Kourou for September

The chart shows the monthly maximum UV Index (UVI) for Kourou 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 Kourou typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec131416161413121313131312
Data source: Kourou 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 Kourou

In September, Kourou, French Guiana, basks in an impressive 334 hours of sunshine, showcasing the region's vibrant climate as it transitions into the heart of the dry season. This month continues the trend of abundant sunlight established during the peak of the summer, with July and August leading the way at 315 and 340 hours, respectively. The consistent sunshine not only brings warmth but also creates an inviting atmosphere for outdoor adventures and cultural experiences. As the year progresses, October follows closely with 339 hours, maintaining the cheerful radiance that characterizes Kourou’s beautiful weather. Overall, the sun-drenched months promise both enjoyment and exploration, reinforcing the appeal of this tropical destination.

Monthly Sunshine Duration in Kourou: September Highlighted

The September sunshine duration represents the total number of hours Kourou 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.
JanFebMarAprMayJunJulAugSepOctNovDec235h243h301h258h232h259h315h340h334h339h289h268h
Data source: Kourou September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Kourou During September

In Kourou, French Guiana, September emerges as a promising month for sunny weather, boasting a 42% chance of sunshine. This marks a notable increase from the preceding months, where sunny days were less frequent, plunging to as low as 10% in May. As the region transitions from the drier season of August, which enjoys a 36% chance, September ushers in a more vibrant climate, leading into October's 30% likelihood. The upward trend from the summer months indicates that September is increasingly becoming a favored time for those seeking brighter days, making it an ideal choice for outdoor activities and exploration.

Percentage of Sunny Days in September in Kourou

The chart illustrates the percentage of sunny days in Kourou 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 Kourou experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec19%18%20%11%10%22%23%37%42%30%17%8%
Data source: Kourou September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Kourou in September

In September, Kourou, French Guiana enjoys a steady 12 hours of daylight, maintaining the trend established in the preceding months. This period of consistent daylight follows a gradual increase from 11 hours in January and February, peaking at 12 hours from March through September. As autumn approaches, daylight begins to dwindle, returning to 11 hours in October. This remarkable stability in daylight duration contributes to the region's vibrant ecosystem and allure for outdoor explorers, reflecting an inviting tropical rhythm that residents and visitors alike treasure throughout the year.

Average Daylight Hours in Kourou for September

The chart illustrates the variation in daylight duration in Kourou throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec11h 50m11h 56m12h 4m12h 13m12h 20m12h 23m12h 22m12h 15m12h 7m11h 59m11h 52m11h 49m
Data source: Kourou daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Kourou

In September, Kourou, French Guiana experiences a soothing average wind speed of 3.0 m/s (7 mph), a continuation of the calm trend observed through the summer months. Following a gradual decline from spring's breezy April, the winds reached a low in July, maintaining a gentle breeze into August and September. This shift indicates a transitional period, as the area prepares for the slightly brisker conditions of October and November, where average wind speeds increase to 3.6 m/s (8 mph). Overall, September's winds offer a tranquil respite, setting the stage for the upcoming seasonal changes while inviting both residents and visitors to enjoy the serene atmosphere.

Average September Wind Speed in Kourou

The chart displays monthly wind speed patterns in Kourou, 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.
JanFebMarAprMayJunJulAugSepOctNovDec5.05.94.94.34.13.02.73.13.0 m/s3.63.64.2
Data source: Kourou September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Kourou Compares to Other Months

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

In comparing the weather between September and January, we observe a slight decrease in average temperatures during January, with a minimum of 23°C (74°F) and a maximum of 29°C (85°F), compared to September's averages of 24°C (75°F) and 31°C (88°F). Both months experience high humidity levels, with January at 70% compared to September's 62%. However, January sees significantly more precipitation, totaling 202 mm (8.0 in) over 23 days, while September has 92 mm (3.6 in) over 16 days. This makes January a wetter month, contributing to a more humid environment overall. For a detailed look at the weather specifics for January, you can visit Kourou weather in January.

September and February exhibit distinct weather patterns, with September featuring slightly warmer average temperatures, ranging from a minimum of 24°C (75°F) to a maximum of 31°C (88°F), and experiencing 92 mm (3.6 in) of precipitation over 16 days. In contrast, February has a minimum temperature of 23°C (75°F), an average of 26°C (79°F), and a maximum of 29°C (84°F), but it is notably wetter, receiving 172 mm (6.8 in) of rainfall across 23 days. Additionally, February shows a higher humidity level of 66% compared to September's 62%. For a closer look at February's conditions, you can check Kourou weather in February.

Comparing the weather between September and March reveals some interesting contrasts. In September, the temperatures are warm, ranging from a minimum of 24°C (75°F) to a maximum of 31°C (88°F), with an average of 27°C (81°F) and a humidity level of 62%. However, this month experiences 92 mm (3.6 inches) of precipitation over 16 days. In contrast, March presents slightly cooler temperatures with minimums still at 24°C (75°F) but a maximum of only 29°C (85°F), averaging 26°C (79°F). Notably, March sees a significant increase in rainfall, with 191 mm (7.5 inches) spread over 25 days and higher humidity at 66%. For a more detailed look at the weather in March, you can check this link: Kourou weather in March.

When comparing the weather in September and April, it's evident that both months offer warm conditions, but they differ significantly in terms of precipitation and overall humidity. In September, temperatures range from a minimum of 24°C (75°F) to a maximum of 31°C (88°F), with an average temperature of 27°C (81°F). This month experiences 92 mm (3.6 in) of rainfall over approximately 16 days, resulting in a humidity level of 62%.

In contrast, April presents slightly cooler temperatures, with a minimum of 23°C (74°F) and a maximum of 29°C (85°F), averaging 26°C (79°F). However, it has considerably more rainfall, totaling 375 mm (14.8 in) spread across 28 days, leading to a higher humidity of 66%. For a deeper insight into April weather specifics, you can visit Kourou weather in April.

When comparing the weather in September and May, both months feature similar minimum temperatures at around 24°C (75°F). However, September tends to be slightly warmer on average, with temperatures peaking at 31°C (88°F), compared to May's maximum of 30°C (86°F). A significant difference lies in precipitation; September receives 92 mm (3.6 in) over 16 days, while May is much wetter, accumulating 541 mm (21.3 in) across 30 days, leading to a higher humidity of 68% during May compared to September's 62%. For more detailed insights on May weather, visit Kourou weather in May.

In comparing the weather between September and June, September offers slightly warmer temperatures, with an average of 27°C (81°F) compared to June's average of 26°C (79°F). While September features a minimum temperature of 24°C (75°F) and a maximum of 31°C (88°F), June closely follows with temperatures ranging from a minimum of 23°C (74°F) to a maximum of 30°C (87°F). However, the contrast in precipitation is quite striking: September experiences 92 mm (3.6 in) of rain over 16 days, whereas June sees significantly heavier rainfall of 448 mm (17.6 in) over 30 days, resulting in higher humidity levels in June at 86% compared to September's 62%. For a more detailed view, check Kourou weather in June.

When comparing the weather in September and July, we can see some notable differences. In September, temperatures range from a minimum of 24°C (75°F) to a maximum of 31°C (88°F), with an average of 27°C (81°F). The month experiences 92 mm (3.6 in) of rain over 16 days, resulting in a lower humidity of 62%. In contrast, July has similar maximum temperatures but with a slightly lower average of 26°C (79°F) and minimum temperatures of 23°C (73°F). However, July is significantly wetter, with 259 mm (10.2 in) of precipitation across 29 days and a higher humidity of 76%. For more detailed information, you can check Kourou weather in July.

In comparing the weather of September and August, both months experienced similar average temperatures, hovering around 27°C (81°F) with maximums reaching 31°C (88°F). However, September had a slightly higher minimum temperature of 24°C (75°F) compared to August’s 23°C (74°F). Precipitation in September totaled 92 mm (3.6 in) over 16 days, whereas August saw more rainfall at 114 mm (4.5 in) over 21 days, resulting in a drier September overall. Additionally, humidity levels were marginally lower in September at 62% compared to August's 65%. For more detailed insights about August’s climate, check out Kourou weather in August.

In September, the weather features a minimum temperature of 24°C (75°F) and averages around 27°C (81°F), peaking at 31°C (88°F). This month experiences a higher precipitation level of 92 mm (3.6 in) over 16 days, with humidity at 62%. In contrast, October maintains similar temperature ranges but sees a reduction in precipitation to 69 mm (2.7 in) spread across 18 days, with a slight increase in humidity to 63%. For more details about the weather specifics in October, you can check Kourou weather in October.

September and November exhibit similar temperature ranges, with both months featuring minimum temperatures around 24°C (75°F), average highs of 27°C (81°F), and peaks reaching 31°C (88°F). However, November tends to be wetter, with total precipitation soaring to 212 mm (8.3 in) over 25 days, compared to September's 92 mm (3.6 in) across 16 days. Additionally, November experiences higher humidity levels at 74%, compared to September's 62%. For more specific details on November weather, you can check this link: Kourou weather in November.

In September, the weather is warm and relatively dry, with average temperatures ranging from a minimum of 24°C (75°F) to a maximum of 31°C (88°F). The month sees an average precipitation of 92 mm (3.6 in) over 16 days, accompanied by a humidity level of 62%. In contrast, December brings cooler conditions, with temperatures averaging between 23°C (74°F) and 29°C (85°F). However, it is significantly wetter, experiencing 322 mm (12.7 in) of rainfall over 30 days and a higher humidity of 79%. For more detailed weather information, you can check Kourou weather in December.

Compare Kourou's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Kourou

September in Kourou showcases a unique climate profile that sets it apart from other months. As the transition to the wet season begins, expect a noticeable increase in rainfall, making it one of the wetter months of the year. While the temperatures remain consistently warm with a comfortable average, the humidity hovers around 62%, adding a refreshing tropical touch to the air. This month is characterized by frequent rain showers, but they typically don't last long, allowing for plenty of opportunities to explore the vibrant surroundings. For those looking to dive deeper into Kourou's atmospheric trends, check out the detailed insights on the Kourou Climate.