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.
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.
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.
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.
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!
UV Risk Categories
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.
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.
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.
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.
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.
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.