Last updated: August 21, 2025
In Rio Negro, Brazil, September brings a delightful climate characterized by mild temperatures. Expect maximum highs reaching 32°C (90°F), while averaging around 18°C (65°F) and dipping to a cool 5°C (42°F) at night. With an average humidity of 82%, the air feels fresh and invigorating. Rainfall is moderate, with a total of 69 mm (2.7 in) spread over 8 days, offering a refreshing respite. This month perfectly balances warmth and occasional showers, making it a pleasant time to experience the lush natural beauty of the region.
In September, Rio Negro, Brazil begins to shake off the lingering chill of winter, showcasing a delightful transition in temperatures. With a minimum of 5°C (42°F) and a pleasant average of 18°C (65°F), the region starts to warm up noticeably. Daytime highs can reach up to 32°C (90°F), marking one of the last hurrahs of summer warmth before the cooler months set in. This month demonstrates an engaging contrast as it bridges the cool remnants of winter with the burgeoning heat of spring, making it an ideal time for outdoor activities and exploration. As temperatures gradually rise, visitors can enjoy the vibrant atmosphere that Rio Negro has to offer.
In September, Rio Negro experiences a notable shift in precipitation, receiving 69 mm (2.7 in) of rain over 8 days. This marks a slight decrease from August's 79 mm (3.1 in), indicating a gradual transition towards drier conditions as the region moves into the latter part of the year. While still wetter than the drier months of July and April, September's rainfall intensity is less than seen earlier in the year, setting the stage for the more substantial precipitation expected in October. The changing patterns highlight not just the seasonal variability, but also a rhythm in rainfall that characterizes the region’s climate as it navigates through the months.
In September, Rio Negro, Brazil experiences a modest humidity level of 82%, a slight rise from the drier months of July and August when humidity dipped to 80% and 79%, respectively. The trend showcases a gradual increase in moisture as the region transitions from the winter months into the spring. Following September, humidity levels maintain this balance into October, indicating a stable and comfortable atmosphere prior to the higher levels seen in the later months of the year. Overall, Rio Negro's climate exhibits a rhythm of humid and drier cycles, with September marking a pivotal point back toward the more humid conditions typical of the region.
In September, Rio Negro, Brazil, experiences a UV Index of 11, classified as extreme, meaning that even short exposures can lead to skin damage—in this case, just 10 minutes unprotected in the sun. This seasonal trend indicates that, as the year progresses from milder months, the UV levels start to rise significantly, peaking in the high summer months of December and January with an extreme rating of 15 and a burn time of only 10 minutes. It's crucial for residents and visitors alike to remain vigilant about sun protection, especially during September, as the risk remains notably high. For more details on UV Index trends throughout the year, check Rio Negro UV Index.
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As September unfolds in Rio Negro, Brazil, residents and visitors alike can bask in the delight of 240 hours of sunshine. This month sits comfortably amid a spectrum of vibrant weather patterns; while it doesn’t reach the dazzling heights of December's 291 hours, it continues the trend of robust sunshine that begins ramping up with the onset of the dry season. Following the xnumber of sunlight hours in the cooler months, September shines brighter than the preceding June and April, signaling a transition towards warmer days. Interestingly, it also serves as a bridge to October's decrease, hinting that the sunny days of the year are not yet over. With sunny skies in abundance, September offers a perfect backdrop for exploring all the beauty that Rio Negro has to offer.
In Rio Negro, Brazil, September brings a 31% chance of sunny weather, fitting neatly within a broader trend of fluctuating sunshine throughout the year. Following the sunnier months of July (53%) and May (44%), September represents a slight decline, echoing the pattern observed as the region transitions into the warmer season. While the chances of sun may not be as high as in earlier months, the likelihood remains favorable compared to the darker days of October (11%) and the early summer months, where the sun's presence drastically diminishes. This makes September a promising choice for those seeking a balance of moderate weather and sunny days in this vibrant part of Brazil.
As September unfolds in Rio Negro, Brazil, the daylight duration remains steady at 11 hours, mirroring the preceding and following months of August and October. This marks a transitional period, as the days begin to lengthen again after the winter months. Following the winter solstice in June, when daylight is at its shortest with just 10 hours, a gradual increase throughout August and into October illuminates the shift towards longer days. This trend culminates in December, when daylight peaks at 13 hours. The rhythmic cycle of daylight in Rio Negro not only reflects seasonal changes but also enriches the vibrant life of the region, offering ample time for exploration and outdoor activities.
As September unfolds in Rio Negro, Brazil, the average wind speed reaches 2.9 m/s (7 mph), marking a delightful transition from the gentle breezes of winter to the more invigorating gusts of spring. This month shows a slight uptick from the preceding months, aligning with an upward trend observed since August. Interestingly, the wind speed in September matches the dynamic energy of October, both showcasing breezy conditions that can invigorate the senses. Throughout the year, Rio Negro's winds tend to fluctuate modestly, maintaining a consistent rhythm, with the warmer months gradually steering towards more spirited breezes. The gradual shift into spring hints at a refreshing promise, offering residents and visitors alike an inviting atmosphere for outdoor pursuits.
Weather in Rio Negro varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Rio Negro, focusing on differences in temperature, rainfall, humidity, and UV levels.
Comparing September and January weather reveals distinct differences in temperature and precipitation. September typically experiences milder temperatures, with a minimum of 5°C (42°F) and an average of 18°C (65°F), while January sees warmer conditions, with a minimum of 13°C (57°F) and an average of 22°C (72°F). The rainfall also varies significantly, as September receives 69 mm (2.7 in) over about 8 days, whereas January has a much higher precipitation level of 150 mm (5.9 in) spread across 18 days. Additionally, both months have high humidity, with September at 82% and January slightly higher at 86%. For more details on January weather, you can check Rio Negro weather in January.
In comparing the weather between September and February, September experiences a broader temperature range with minimums dipping to 5°C (42°F) and maximums reaching 32°C (90°F), while February tends to be warmer overall, with min temperatures starting at 11°C (51°F) and maxing out at 34°C (94°F). Precipitation is more frequent in February, with 124 mm (4.9 in) falling over 15 days compared to September's 69 mm (2.7 in) across 8 days. Humidity levels remain relatively high for both months, with September at 82% and February slightly higher at 83%. For more detailed insights about the February weather in this region, you can check Rio Negro weather in February.
In September, the weather features a wide temperature range from a minimum of 5°C (42°F) to a maximum of 32°C (90°F), with an average of 18°C (65°F). The month experiences about 69 mm (2.7 in) of precipitation over 8 days, and humidity levels are relatively high at 82%. In contrast, March typically sees a warmer climate, with minimum temperatures of 12°C (53°F), an average of 21°C (70°F), and similar maximum highs of 32°C (89°F). However, March is wetter, with 109 mm (4.3 in) of rain falling over 15 days, and humidity increases slightly to 85%. For a more detailed look at the weather in March, check out Rio Negro weather in March.
In comparing the weather conditions between September and April, both months showcase an average temperature of 18°C (65°F), but September tends to feature a wider temperature range, with minimums reaching 5°C (42°F) and maximums peaking at 32°C (90°F). In contrast, April's temperatures are slightly cooler, with a minimum of 4°C (39°F) and a maximum of 30°C (86°F). Additionally, September experiences higher precipitation, averaging 69 mm (2.7 in) over 8 days, compared to April's 47 mm (1.9 in) over 5 days, indicating a drier climate during the latter month. Both months maintain relatively high humidity levels, with September at 82% and April at 85%. For more detailed insights into Rio Negro weather in April, you can visit Rio Negro weather in April.
When comparing the weather in September and May, we see distinct variations in temperature and precipitation. September typically enjoys a wider temperature range, with minimums around 5°C (42°F) and maximums reaching up to 32°C (90°F), resulting in an average temperature of 18°C (65°F). In contrast, May has slightly cooler temperatures, with minimums at 2°C (35°F) and maximums peaking at 28°C (83°F), averaging 16°C (61°F). Precipitation levels are also notable; September receives 69 mm (2.7 in) of rain over 8 days, while May records a higher 87 mm (3.4 in) during the same number of days. Additionally, May's humidity is slightly higher at 86%, compared to September's 82%. For more detailed weather information, you can check Rio Negro weather in May.
In comparing the weather of September and June, September tends to be warmer, with average temperatures reaching 18°C (65°F) and a maximum of 32°C (90°F), whereas June has a cooler average of 15°C (59°F) and peaks at 26°C (79°F). September also experiences less precipitation, totaling 69 mm (2.7 in) over 8 days, compared to June's 118 mm (4.6 in) across 10 days. Humidity levels are relatively similar, with September at 82% and June slightly higher at 85%. For more details on June weather, you can check Rio Negro weather in June.
In comparing the weather between September and July, notable differences emerge in temperature and precipitation levels. September boasts a broader temperature range with a minimum of 5°C (42°F), an average of 18°C (65°F), and a maximum of 32°C (90°F), making it generally warmer than July, which has a minimum of -4°C (26°F), an average of 14°C (57°F), and a maximum of 26°C (79°F). Additionally, September experiences more rainfall, with 69 mm (2.7 in) over 8 days, compared to July’s 27 mm (1.0 in) across just 4 days. Both months maintain high humidity levels, with September at 82% and July slightly lower at 80%. For more detailed insights, you can check out Rio Negro weather in July.
In comparing the weather of September and August, September brings a notably warmer atmosphere with an average temperature of 18°C (65°F), up from August's 15°C (59°F). While both months experience precipitation, September sees slightly less at 69 mm (2.7 in) over 8 days, compared to August's 79 mm (3.1 in) over 7 days. Humidity levels are also higher in September, at 82%, compared to 79% in August. Overall, September tends to be warmer and slightly wetter than August. For more detailed information about August weather, you can visit Rio Negro weather in August.
September and October exhibit noticeable differences in weather patterns while still maintaining similar average temperatures. In September, temperatures range from a minimum of 5°C (42°F) to a maximum of 32°C (90°F), with an average of 18°C (65°F). This month experiences 69 mm (2.7 in) of precipitation over 8 days, maintaining a consistent humidity level of 82%. Conversely, October sees a slight increase in minimum temperatures at 6°C (44°F) and a higher maximum of 34°C (93°F), while the average remains stable at 18°C (65°F). However, October is considerably wetter, with precipitation rising to 147 mm (5.8 in) over 14 days, while humidity remains steady at 82%. For more details, you can check the Rio Negro weather in October.
In September, temperatures typically range from a cool 5°C (42°F) to a warm 32°C (90°F), with an average of 18°C (65°F). With 69 mm (2.7 in) of precipitation spread across about 8 days, the month experiences relatively high humidity at 82%. In contrast, November brings slightly milder temperatures, with a minimum of 8°C (46°F), an average of 19°C (67°F), and a maximum of 31°C (89°F). However, it is also wetter, receiving 103 mm (4.1 in) of rainfall over 13 days and with humidity rising to 86%. For more detailed insights about November weather, you can check Rio Negro weather in November.
In September, the weather in Rio Negro features a minimum temperature of 5°C (42°F) and an average of 18°C (65°F), with highs reaching up to 32°C (90°F). The month sees about 69 mm (2.7 in) of precipitation over approximately 8 days, coupled with a humidity level of 82%. By contrast, December brings warmer conditions with minimum temperatures around 11°C (52°F) and an average of 21°C (70°F), peaking at a maximum of 34°C (93°F). Rainfall increases significantly to 137 mm (5.4 in) across 17 days, and humidity rises slightly to 88%. For more detailed insights, you can visit Rio Negro weather in December.
As September rolls in, Rio Negro begins to transition into spring, showcasing a unique blend of weather that sets it apart from the winter months. Although temperatures can soar up to 32°C, the average settles at a comfortable 18°C, welcoming residents and visitors alike. The arrival of rainfall, with about 69 mm over 8 days, helps to revitalize the lush landscape, resulting in a noticeable increase in humidity, which hovers around 82%. This month serves as a gentle bridge between the cooler, drier winter and the balmy, wetter summer, making it an ideal time to enjoy the vibrant natural surroundings. For more details on the climate throughout the year, check out Rio Negro Climate.