September Weather in Rio de Janeiro, Brazil

Last updated: August 21, 2025

September in Rio de Janeiro brings a delightful transition into spring, characterized by temperatures ranging from a warm 16°C (60°F) to a scorching 35°C (96°F), with an average of 23°C (74°F). The city experiences moderate humidity at 68%, making the weather feel pleasantly balmy. While the day might invite plenty of sunshine, visitors should be prepared for occasional showers, as precipitation amounts to 55 mm (2.2 in) spread out over 8 days. This combination of warmth and occasional rain makes September an ideal time to explore the vibrant landscapes and culture that Rio has to offer.

September Temperature in Rio de Janeiro

In September, Rio de Janeiro begins to shed the cooler embrace of winter, welcoming spring with mild temperatures that set the stage for a vibrant transition. With a minimum of 16°C (60°F) and an average of 23°C (74°F), the city enjoys a comfortable climate perfect for outdoor activities. The maximum temperature climbs to 35°C (96°F), hinting at the warmth that will dominate as summer approaches. This month marks a shift from July and August's cooler readings, showcasing a steady rise in temperature. Visitors can expect sunny days ideal for exploring Rio’s stunning beaches and iconic landmarks, reminding us that the city's vibrant life flourishes as the days grow warmer.

September Weather in Rio de Janeiro: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Rio de Janeiro, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Rio de Janeiro, 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).
JanFebMarAprMayJunJulAugSepOctNovDec818080767372707073757578
Data source: Temperature data for Rio de Janeiro 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 Rio de Janeiro

In September, Rio de Janeiro experiences a notable shift in precipitation as the region transitions towards the wetter months of spring. With an average rainfall of 55 mm (2.2 in) over 8 days, September marks a decrease from the heavier downpours earlier in the year, especially the peaks in February and March with 146 mm (5.7 in) and 163 mm (6.4 in), respectively. This month serves as a gentle pause before the October resurgence, which typically brings increased rainfall with 98 mm (3.8 in) anticipated over more frequent precipitation days. Overall, September's moderate rainfall hints at the upcoming seasonal changes, making it a transitional time for both the climate and the vibrant life of the city.

September Precipitation Trends in Rio de Janeiro

The chart displays monthly precipitation patterns in Rio de Janeiro, 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 Rio de Janeiro, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec11214616395784438755598135143
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Rio de Janeiro

As September rolls into Rio de Janeiro, a noticeable shift in humidity levels marks the transition to spring. With humidity dipping to 68%, this month experiences one of the lowest moisture levels of the year, following the preceding months' higher averages. The gradual decrease from a humid August, which sits at 73%, paves the way for a more pleasant climate as the city prepares for the warmer months ahead. This trend continues into October, where humidity further declines to 61%, signaling a trend of increasing comfort as summer approaches. Such fluctuations not only highlight Rio’s dynamic weather patterns but also offer a reprieve for both locals and visitors seeking to enjoy the city's vibrant outdoor marvels without the heavy blanket of humidity characteristic of earlier months.

September Average Humidity in Rio de Janeiro

This chart illustrates the average monthly humidity levels in Rio de Janeiro, 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 Rio de Janeiro is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%85%86%83%81%80%76%73%68%61%72%75%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Rio de Janeiro

As September rolls in, Rio de Janeiro residents and visitors can expect a UV Index of 11, categorized as extreme, with a quick burn time of just 10 minutes. This marks a shift back to higher UV levels after a slightly lower August, where the index dipped to 9. From September onward, the UV Index remains consistently high, peaking again in December with an extreme rating of 15. It's crucial to stay protected during this period, mirroring the patterns seen in earlier months like January and February. For more detailed data on UV exposure, check out the Rio de Janeiro UV Index. Enjoy the sun, but don’t forget to apply that sunscreen!

Maximum UV Index Levels in Rio de Janeiro for September

The chart shows the monthly maximum UV Index (UVI) for Rio de Janeiro 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 Rio de Janeiro typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec15141310767911121315
Data source: Rio de Janeiro 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 Rio de Janeiro

As September arrives in Rio de Janeiro, the city basks in 293 hours of glorious sunshine, making it a delightful time for beachgoers and outdoor enthusiasts. This marks a notable peak following the winter months, where sunlight gradually increased from 275 hours in August. The trend illustrates a consistent ascent in daylight hours as the year progresses, peaking in December with 318 hours of sunshine. Notably, September's sun-filled days signal a transition into warmer weather, ushering locals and tourists alike into the vibrant atmosphere that characterizes this iconic city. With an array of cultural events and breathtaking landscapes, September in Rio is a radiant invitation to soak up the sun and embrace the lively spirit of Brazil.

Monthly Sunshine Duration in Rio de Janeiro: September Highlighted

The September sunshine duration represents the total number of hours Rio de Janeiro 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.
JanFebMarAprMayJunJulAugSepOctNovDec270h271h309h296h282h276h290h275h293h281h284h318h
Data source: Rio de Janeiro September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Rio de Janeiro During September

In September, Rio de Janeiro enjoys a reasonably favorable climate, with a 49% chance of sunny weather. While it doesn't quite match the peak sunlit days of the mid-year months like July and August, which boast chances of 59% and 60% respectively, September maintains a solid footing alongside April and June. As the city transitions from winter to spring, one can expect a blend of lingering coolness and the promise of warmer days ahead, making it an appealing time for outdoor activities, although travelers should still be prepared for the possibility of clouds. The trend indicates a gradual shift into sunnier days as the year approaches its peak summer season, with October showing a sharp drop to 18%, signaling the end of this charming transitional period.

Percentage of Sunny Days in September in Rio de Janeiro

The chart illustrates the percentage of sunny days in Rio de Janeiro 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 Rio de Janeiro experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec33%33%50%54%49%54%59%60%49%18%36%41%
Data source: Rio de Janeiro September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Rio de Janeiro in September

As September rolls into Rio de Janeiro, the city enjoys about 11 hours of daylight, a continuation of the gradual shifts that characterize the southern hemisphere's approach to spring. Following the peak brightness of January and February with their generous 13 hours and 12 hours of daylight respectively, the duration starts to subtly decline from March through May, settling at a modest 10 hours in the depths of winter. However, as August transitions into September, daylight begins to reclaim its strength, reflecting a broader trend of increasing brightness that will continue into the summer months. This rhythmic pattern not only showcases the natural ebb and flow of daylight but also sets the perfect backdrop for outdoor adventures in the vibrant city, where each hour invites exploration and enjoyment.

Average Daylight Hours in Rio de Janeiro for September

The chart illustrates the variation in daylight duration in Rio de Janeiro throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec13h 20m12h 50m12h 11m11h 31m10h 59m10h 44m10h 52m11h 20m11h 57m12h 37m13h 12m13h 30m
Data source: Rio de Janeiro daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Rio de Janeiro

In September, Rio de Janeiro experiences a gentle yet invigorating shift in its winds, with average gusts reaching 3.7 m/s (8 mph). This marks a noticeable increase compared to the preceding months, as the city transitions from the calmer summer breezes of earlier in the year. With this slight uptick in wind speed, September becomes a time when the air feels fresher, hinting at the approach of spring in the Southern Hemisphere. As the monthly averages demonstrate a gradual rise from 2.1 m/s in February to the more pronounced 3.9 m/s in October, it's clear that September serves as a pivotal moment in this annual pattern, blending warmth with a refreshing energy that enchants both locals and visitors alike.

Average September Wind Speed in Rio de Janeiro

The chart displays monthly wind speed patterns in Rio de Janeiro, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.92.12.43.32.42.93.03.53.7 m/s3.93.12.8
Data source: Rio de Janeiro September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Rio de Janeiro Compares to Other Months

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

In September, the weather in Rio de Janeiro features a pleasant range of temperatures with a minimum of 16°C (60°F) and an average of 23°C (74°F), reaching a maximum of 35°C (96°F). The month experiences about 55 mm (2.2 in) of precipitation over approximately 8 days, while humidity levels are around 68%. In contrast, January is warmer, with temperatures fluctuating from a minimum of 21°C (69°F) to an average of 27°C (81°F), peaking again at 35°C (95°F). This month sees increased rainfall, totaling 112 mm (4.4 in) over about 13 days, and higher humidity at 85%. For more details on January weather, visit Rio de Janeiro weather in January.

When comparing the weather in September and February, there are noticeable differences in temperature, precipitation, and humidity. September tends to be milder, with average temperatures ranging from a minimum of 16°C (60°F) to a maximum of 35°C (96°F), while February is warmer with temperatures ranging from 21°C (71°F) to the same maximum of 35°C (95°F). Precipitation in September is relatively low at 55 mm (2.2 in) spread over 8 days, whereas February experiences significantly higher rainfall of 146 mm (5.7 in) across 17 days. Additionally, February features higher humidity levels at 85% compared to September's 68%. For more detailed information, check out Rio de Janeiro weather in February.

In September, the weather tends to be warm and fairly dry, with average temperatures ranging from a minimum of 16°C (60°F) to a maximum of 35°C (96°F). The month sees around 55 mm (2.2 in) of precipitation over approximately 8 days, along with a humidity level of 68%. In contrast, March brings higher temperatures with a minimum of 20°C (68°F) and average highs reaching 35°C (94°F). However, it's also much wetter, with 163 mm (6.4 in) of rainfall spread over 17 days and increased humidity at 86%. For more details, you can check Rio de Janeiro weather in March.

When comparing the weather in September and April, September typically showcases warmer temperatures with a minimum of 16°C (60°F) and an average around 23°C (74°F), peaking at 35°C (96°F). In contrast, April tends to be slightly cooler with a minimum of 18°C (65°F) and an average temperature of 25°C (76°F), reaching a maximum of 34°C (94°F). However, April experiences more precipitation, totaling 95 mm (3.7 in) over 13 days, compared to September's 55 mm (2.2 in) across 8 days. Additionally, humidity levels are higher in April at 83% compared to September's 68%. For more detailed information, check out Rio de Janeiro weather in April.

The weather in September and May exhibits some similarities and differences. Both months have an average temperature around 23°C (74°F), with September reaching a maximum of 35°C (96°F) compared to May's peak of 33°C (91°F). However, May tends to be slightly more humid, with a humidity level of 81% compared to September's 68%. Precipitation is also higher in May, with 77 mm (3.1 in) of rain over 10 days, while September sees 55 mm (2.2 in) over 8 days. For more detailed information, you can check Rio de Janeiro weather in May.

In comparing the weather of September and June, both months maintain similar minimum temperatures, averaging around 16°C (60°F). However, September tends to be hotter, with average highs reaching 35°C (96°F), while June's maximum temperature is more moderate at 32°C (89°F). Additionally, September experiences slightly higher rainfall, accumulating 55 mm (2.2 in) over 8 days, compared to June's 44 mm (1.7 in) over 9 days. Humidity levels are also noteworthy; September has an average of 68%, which is lower than June's more humid average of 80%. For a detailed look at June's weather specifics, you can check Rio de Janeiro weather in June.

In comparing the weather of September and July, September tends to be warmer, with average temperatures reaching 23°C (74°F) compared to July's average of 21°C (70°F). September also sees higher maximum temperatures, peaking at 35°C (96°F) versus July's maximum of 32°C (91°F). While both months experience some rain, September has slightly more precipitation at 55 mm (2.2 in) over 8 days, compared to July's 38 mm (1.5 in) over 7 days. However, July has a higher humidity level at 76%, compared to September's 68%, making July feel more humid overall. For more detailed information on July weather, you can check Rio de Janeiro weather in July.

In comparing the weather patterns of September and August, September tends to be warmer, with average temperatures rising to 23°C (74°F) from a lower average of 21°C (70°F) in August. The maximum temperatures also see an increase, reaching up to 35°C (96°F) in September, compared to August's 33°C (91°F). However, September experiences slightly less precipitation, totaling 55 mm (2.2 in) over 8 days, in contrast to August's 75 mm (3.0 in) over 11 days. Humidity levels are relatively high in both months, with September at 68% and August slightly higher at 73%. For more detailed insights into the weather, you can check Rio de Janeiro weather in August.

September typically experiences warmer temperatures, with averages around 23°C (74°F) and maximums reaching up to 35°C (96°F). In contrast, October sees a slight increase in average temperature to 24°C (75°F), with maximums peaking at 37°C (99°F). While September has moderate precipitation at 55 mm (2.2 in) over 8 days, October is significantly wetter, receiving 98 mm (3.8 in) across 15 days. Interestingly, the humidity in October is lower at 61%, compared to September's 68%, making the slightly warmer October feel less sticky. For more details, check Rio de Janeiro weather in October.

In September, the weather in Rio de Janeiro features a comfortable average temperature of 23°C (74°F), with highs reaching up to 35°C (96°F) and a minimum temperature of 16°C (60°F). Precipitation is relatively low at 55 mm (2.2 in), occurring over about 8 days, and humidity is around 68%.

In contrast, November sees slightly warmer temperatures, with an average of 24°C (75°F) and similar maximum highs of 35°C (94°F). However, November is wetter, with a significant increase in rainfall to 135 mm (5.3 in) spread over 17 days, and humidity rises to 72%. For more details, check out Rio de Janeiro weather in November.

When comparing the weather in September and December, September tends to be slightly cooler with average temperatures ranging from a minimum of 16°C (60°F) to a maximum of 35°C (96°F) and an average of 23°C (74°F). The month experiences about 55 mm (2.2 in) of precipitation over 8 days, contributing to a humidity level of 68%. In contrast, December offers warmer conditions with minimum temperatures of 18°C (65°F) and averages reaching 25°C (78°F). However, it also sees increased rainfall, totaling 143 mm (5.6 in) across 17 days, resulting in higher humidity at 75%. For more detailed information on December weather, you can check Rio de Janeiro weather in December.

Compare Rio de Janeiro's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Rio de Janeiro

As September unfolds in Rio de Janeiro, visitors are greeted with the transitioning warmth of spring, setting it apart from the cooler winter months. With temperatures rising to a pleasant average of 23°C, the city starts to shed its chill, inviting outdoor adventures. The somewhat moderate humidity of 68% paired with occasional rain—typically just 8 days of precipitation—ensures a refreshing atmosphere without the drenching downpours typical of summer. This combination makes September an excellent time for exploring the vibrant beaches and lush landscapes of Rio. For a comprehensive understanding of how the city's weather shifts throughout the year, check out Rio de Janeiro Climate.