Last updated: August 21, 2025
In September, São Sebastião, Brazil experiences warm and inviting weather, with maximum temperatures often reaching up to 34°C (93°F) and an average hovering around a comfortable 21°C (70°F). As the month unfolds, temperatures dip to a minimum of 15°C (60°F), offering a pleasant respite from the heat. This month also sees a fair amount of precipitation, totaling around 95 mm (3.7 in) over approximately 11 days, creating a vibrant atmosphere amidst the coastal beauty. Elevated humidity levels of 58% contribute to the lively tropical environment, making September a captivating time to visit São Sebastião.
In September, São Sebastião begins to transition into warmer weather as the lingering chill of winter fades. The month showcases a minimum temperature of 15°C (60°F), with average daily readings around 21°C (70°F) and a notable peak of 34°C (93°F) on hotter days. This rise in temperatures indicates a steady shift from the cooler months, emphasizing a return to the tropical warmth that characterizes the region. As spring approaches, the comfortable conditions make September an ideal time for outdoor activities, inviting both locals and tourists to enjoy the stunning beaches and vibrant landscapes. The pleasant climate and increasing heat signal the start of a lively season ahead.
In September, Sao Sebastiao experiences relatively moderate rainfall, with 95 mm (3.7 in) of precipitation over 11 days. This marks a notable decrease compared to the heavier downpours of the preceding months, such as February and March, which recorded 277 mm (10.9 in) and 247 mm (9.7 in), respectively. Following the drier months of July and August, September's rainfall represents a slight uptick, yet the overall trend indicates a gradual transition into the wetter season. As the year progresses towards October, where precipitation peaks again at 161 mm (6.3 in), September serves as a gentle reminder of the impending climatic shift in this vibrant coastal region.
As the seasons shift in São Sebastião, Brazil, September marks a notable drop in humidity, reaching a comfortable 58%. This decline follows a gradual decrease from the highs of 88% in January and February, suggesting a transition into drier months. August’s humidity level of 65% sets the stage for this change, demonstrating a shift towards increasingly pleasant weather. Such a trend continues into October when humidity levels further decrease to 50%, creating an ideal atmosphere for outdoor activities and exploration. Overall, September's dip in humidity not only signifies a welcome respite from the summer mugginess but also hints at the arrival of more refreshing conditions as the year progresses.
In September, Sao Sebastiao, Brazil, experiences a UV Index of 11, classifying it within the extreme exposure category. This indicates that a burn can occur in just 10 minutes of unprotected sun exposure. As we transition from winter to spring, the UV levels reflect a slight rebound from the lower levels seen in the cooler months. Notably, September's UV Index aligns with the summer months of April and October, underscoring a consistent trend of intensified UV radiation in the region. As the year progresses, residents and visitors alike should remain vigilant, utilizing sun protection to mitigate the risks associated with high UV exposure. For more details, check out Sao Sebastiao UV Index.
UV Risk Categories
September in São Sebastião, Brazil, brings a delightful flourish of sunshine, boasting 290 hours of radiant daylight. As the summer transitions from the scorching heights of March, which enjoys a peak of 305 hours, the month maintains a robust amount of sunlight that sets the stage for outdoor adventures. While the sun dips to 261 hours in June, September rejuvenates the spirit as it outshines the cooler months of July and August. Interestingly, the trend of increasing sunlight continues into November, demonstrating that São Sebastião remains a beacon of warmth and vibrancy as the year draws to a close. The consistency of abundant sunshine throughout the year makes September a perfect time to soak up the sun and relish the stunning coastal beauty.
In Sao Sebastiao, Brazil, September brings a moderate likelihood of sunny weather, with the chance of sun at 38%. This marks a notable decrease from the peak summer months of July and August, where sunshine probabilities soar to 59% and 52%, respectively. As the vibrant hues of winter transition into spring, the city experiences fluctuating sunny days, making September a transitional month. Following this, the chances dip further as October approaches, settling at just 18%, indicating that the most reliable sunny days are indeed behind. Overall, while September offers a decent chance for sunshine, it’s part of a broader trend of diminishing sunny conditions as the year progresses towards the rainy season.
In Sao Sebastiao, Brazil, the rhythm of daylight unfolds beautifully throughout the year, with September marking a gentle transition as it offers 11 hours of sunlight. This month typically sees a return to longer days after the drop in daylight during the cooler months of May through August, which consistently feature only 10 to 11 hours of light. As the seasons shift from winter to spring, September's daylight duration aligns with that of April, hinting at a gradual increase in brightness ahead. Following September, October and November promise even longer days, eventually culminating in the lush, sun-drenched months of December and January, where daylight peaks at 13 hours. This subtle increase in daylight not only enriches the landscape but also invigorates the spirit of those enjoying leisure and activity in this coastal paradise.
As September unfolds in São Sebastião, the coastal town begins to embrace a noticeable uptick in wind speed, registering an average of 3.3 m/s (7 mph). This gentle breeze offers a refreshing contrast to the calmer months preceding it, where winds hovered around 2.2 to 2.6 m/s between January and July. The transition into late summer signals a shift, as August experiences a rise to 3.1 m/s, paving the way for September's invigorating gusts. Looking ahead, the winds will continue to strengthen into October, reaching 4.1 m/s (9 mph), fostering an environment perfect for outdoor activities. Thus, September serves as a delightful bridge from mild breezes to a more robust wind pattern, inviting locals and visitors alike to embrace the joys of the season.
Weather in Sao Sebastiao varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Sao Sebastiao, focusing on differences in temperature, rainfall, humidity, and UV levels.
In September, the weather in São Sebastião tends to be warm, with temperatures ranging from a minimum of 15°C (60°F) to an average of 21°C (70°F) and a maximum of 34°C (93°F). The month sees around 95 mm (3.7 in) of precipitation over approximately 11 days, with humidity levels at 58%. In contrast, January brings warmer conditions, with a minimum of 20°C (69°F), an average of 26°C (79°F), and a maximum of 32°C (90°F). However, January is also characterized by significantly higher precipitation, totaling 206 mm (8.1 in) over 19 days and elevated humidity levels at 88%. For more details on January's weather, you can check this link: Sao Sebastiao weather in January.
September and February present distinct weather patterns in the region. In September, temperatures typically range from a minimum of 15°C (60°F) to a maximum of 34°C (93°F), with an average of 21°C (70°F). The humidity is moderate at 58%, and the month sees about 95 mm (3.7 in) of precipitation over 11 days. In contrast, February offers warmer temperatures, with a minimum of 20°C (68°F), an average of 25°C (77°F), and a maximum of 32°C (90°F). However, it is also much wetter, accumulating 277 mm (10.9 in) of rainfall distribution over 21 days, and significantly higher humidity at 88%. For a closer look at February weather specifics, visit Sao Sebastiao weather in February.
When comparing the weather in September and March, notable differences emerge. September experiences cooler minimum temperatures, ranging from 15°C (60°F) to a maximum of 34°C (93°F), with an average of 21°C (70°F) and relatively moderate humidity at 58%. In contrast, March sees a warmer temperature spectrum, starting with a minimum of 19°C (66°F) and peaking at 32°C (89°F), averaging 25°C (77°F), but with significantly higher humidity at 87%. Additionally, March is much wetter, with precipitation totaling 247 mm (9.7 in) across 20 days, compared to September's 95 mm (3.7 in) over 11 days. For more details, you can check Sao Sebastiao weather in March.
In September, temperatures range from a minimum of 15°C (60°F) to a maximum of 34°C (93°F), with an average of 21°C (70°F). The month experiences moderate precipitation, totaling 95 mm (3.7 in) over about 11 days, accompanied by a humidity level of 58%. In contrast, April features slightly warmer temperatures, with a minimum of 17°C (64°F) and a maximum of 32°C (89°F), averaging 23°C (74°F). However, it also sees increased rainfall, accumulating 125 mm (4.9 in) across 15 days, and higher humidity at 84%. For a closer look at April weather specifics, you can refer to Sao Sebastiao weather in April.
When comparing the weather in September and May, both months feature similar average temperatures, hovering around 21°C (70°F). However, September sees greater temperature variability with a maximum reaching 34°C (93°F), while May's maximum is milder at 28°C (83°F). In terms of precipitation, May is slightly wetter, accumulating 119 mm (4.7 in) compared to September's 95 mm (3.7 in), and both months experience rainfall on 11 days. Humidity in May is noticeably higher at 79%, compared to September's 58%, making May feel more humid and tropical. For a detailed look at the weather specifics, you can refer to Sao Sebastiao weather in May.
In comparing the weather of September and June, we see some notable differences. September features a wider temperature range with a minimum of 15°C (60°F) and maximum of 34°C (93°F), offering warmer days on average compared to June, which has a maximum temperature of 30°C (86°F). However, June experiences slightly higher humidity at 77%, while September's humidity is more moderate at 58%. Both months have similar levels of precipitation, with September receiving 95 mm (3.7 in) over about 11 days and June with 100 mm (4.0 in) over 12 days. For more detailed information about June weather specifically in Sao Sebastiao, you can check Sao Sebastiao weather in June.
In comparing the weather between September and July, September tends to be warmer with average temperatures reaching 21°C (70°F) and maximum highs of 34°C (93°F), while July features cooler averages around 20°C (67°F) and a maximum of 29°C (85°F). Precipitation also varies, with September experiencing more rain at 95 mm (3.7 in) over 11 days compared to July's 63 mm (2.5 in) over 6 days. Additionally, humidity levels are higher in July at 72%, while September sees a slightly lower humidity of 58%. For those interested in the specifics of July's weather patterns, you can find more information here: Sao Sebastiao weather in July.
September generally experiences warmer temperatures compared to August, with minimums rising from 13°C (56°F) to 15°C (60°F) and averages increasing from 19°C (67°F) to 21°C (70°F). The maximum temperature in September can reach up to 34°C (93°F), compared to 31°C (88°F) in August. Precipitation levels decrease slightly in September, measuring 95 mm (3.7 in) over 11 days, whereas August sees a higher total of 116 mm (4.6 in) over the same number of days. Additionally, humidity is lower in September at 58% compared to 65% in August, contributing to a more comfortable feel during the transition into early autumn. For a more detailed look at August's climate, you can visit Sao Sebastiao weather in August.
In September, the weather is typically warm with average temperatures ranging from a minimum of 15°C (60°F) to a maximum of 34°C (93°F), accompanied by moderate precipitation of 95 mm (3.7 in) over 11 rainy days and a humidity level of 58%. In contrast, October brings slightly warmer temperatures, with an average of 22°C (71°F) and highs reaching up to 36°C (96°F). However, October is also wetter, experiencing around 161 mm (6.3 in) of precipitation over 19 days and lower humidity at 50%. For more details on the weather in October, you can visit Sao Sebastiao weather in October.
In comparison to September, November experiences slightly warmer temperatures with a minimum of 16°C (60°F) and an average of 22°C (72°F), compared to September's minimum of 15°C (60°F) and average of 21°C (70°F). While the maximum temperature in November reaches up to 31°C (88°F), September sees a higher peak of 34°C (93°F). However, November is notably wetter, with a total precipitation of 176 mm (6.9 in) over 18 days, compared to September's 95 mm (3.7 in) over 11 days. Humidity levels also rise in November to 75%, up from September's 58%. For more detailed insights into the weather in November, check out Sao Sebastiao weather in November.
In September, the weather features a minimum temperature of 15°C (60°F) and an average of 21°C (70°F), with highs reaching up to 34°C (93°F). This month experiences approximately 95 mm (3.7 in) of precipitation over 11 days, accompanied by a humidity level of 58%. In contrast, December brings warmer temperatures, with a minimum of 18°C (64°F) and an average of 24°C (75°F), peaking at 31°C (88°F). However, December also sees an increase in rainfall, totaling 197 mm (7.7 in) across 20 days, and higher humidity at 80%. For more detailed insights into December weather, you can visit Sao Sebastiao weather in December.
As September unfolds in Sao Sebastiao, it presents a delightful transition into spring, marked by a warm average temperature that encourages outdoor activities. Unlike the sweltering heat of the peak summer months, September offers an appealing mix of comfortable highs and cooler evenings, making it an ideal time for exploration. While slight rain showers may surprise visitors, they are generally brief, contributing to the region's lush beauty rather than detracting from it. With humidity levels at a moderate 58%, the air feels refreshing amidst the tropical ambiance. To delve deeper into what to expect throughout the year, check out Sao Sebastiao Climate.