Last updated: August 21, 2025
September in São Luís, Brazil offers a warm tropical atmosphere, characterized by maximum temperatures reaching 31°C (88°F) and an inviting average of 27°C (82°F). With minimum temperatures around 26°C (78°F), the climate is perfect for enjoying outdoor activities. Rainfall is relatively low, with just 21 mm (0.8 in) of precipitation spread over approximately five days, resulting in a humidity level of 51% that balances comfort and heat. Visitors can expect a mix of sunny days and brief showers, making September an ideal time to explore this vibrant coastal city.
In September, São Luís, Brazil, experiences a subtle shift in temperatures as the dry season progresses. The minimum temperature rises slightly to 26°C (78°F), while the average remains stable at 27°C (82°F). Daytime warmth peaks at a comfortable 31°C (88°F), making it ideal for outdoor adventures. This month marks a transition, as the city approaches its warmer months, with the delightful humidity of the previous months beginning to ease just a bit. Overall, September offers a pleasant climate that invites both relaxation and exploration in this vibrant coastal city.
September in São Luís, Brazil, marks a notable shift in precipitation patterns, with rainfall plummeting to just 21 mm (0.8 in) over a mere 5 days. This dip follows the significant downpours of the preceding months, particularly March, which recorded a staggering 483 mm (19.0 in). As the dry season begins to take hold, September's rainfall is a stark contrast to the earlier months characterized by frequent storms. The dramatic decrease in both rainfall amount and rainy days signals a transitional period, as the city prepares for October, which anticipates a slight uptick in precipitation. Overall, September serves as a bridge between the heavy rains of winter and the drier days ahead.
In September, Sao Luis experiences a noteworthy decline in humidity, dipping to a comfortable 51%. This marks the lowest level of the year, following a gradual decrease from the peak seen in earlier months, where humidity levels reached as high as 92% in April. As the dry season approaches, the marked drop from August’s 55% indicates a shift towards more pleasant weather, providing a welcome respite from the sweltering mugginess of the first half of the year. With this lower humidity, September offers an ideal time for outdoor activities, allowing both residents and visitors to enjoy the vibrant culture and stunning landscapes of this beautiful coastal city.
As September rolls into Sao Luis, Brazil, residents and visitors alike should brace themselves for an intense UV experience, with the UV Index lingering at 13, classified as extreme. This level is consistent with the preceding months, maintaining the high standard set throughout the year, where the UV Index varies between 11 and 16. With a burn time of just 10 minutes, it’s crucial to take proper precautions, such as wearing sunblock and protective clothing. This trend of extreme UV exposure serves as a reminder to always stay sun-safe. For more details, visit Sao Luis UV Index.
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As September unfolds in São Luís, Brazil, the city bathes in 338 hours of radiant sunshine, a continuation of its idyllic summer glow. The trend of abundant sunlight that began in June peaks in the late winter months, with August setting the stage with a remarkable 349 hours. This gradual increase not only highlights the region's warm embrace of summer's end but also ensures that outdoor enthusiasts can revel in the beauty of the coastal city. With October bringing in an even brighter 350 hours, the sunshine shows no signs of fading, creating an inviting atmosphere for both locals and visitors alike. As the days lengthen, São Luís becomes a vibrant canvas painted with golden rays, promising memorable experiences under its cheerful skies.
In Sao Luis, Brazil, the likelihood of enjoying sunny weather significantly improves as the year progresses. Starting with a modest 18% in January, the chances gradually rise, reaching their peak in August at a notable 66%. As September rolls in, residents and visitors can anticipate a solid 56% chance of sunshine, making it one of the more favorable months for clear skies. This trend indicates a steady shift toward sunnier conditions from mid-year onward, but with October following closely behind at 52%, September stands out as a delightful time to bask in the warm tropical sun before the rainy season begins to reassert itself. Thus, if you’re planning a visit, September offers a refreshing balance of sun and warmth, ideal for outdoor exploration.
Throughout the year, Sao Luis, Brazil, enjoys a consistently generous amount of daylight, creating a vibrant atmosphere for its residents and visitors alike. From January to April, the city basks in a stable 12 hours of sunlight each day, fostering a sense of balance and harmony. As the calendar turns to May, daylight begins to gently decline to 11 hours, a trend that continues through the following months of June and July. However, as August rolls in, a resurgence occurs with daylight returning to 12 hours, persisting through September and on into the later months of the year. This rhythmic pattern of daylight not only impacts daily life in Sao Luis but also enhances its stunning coastal allure, making every month an inviting time to experience its natural beauty.
As September rolls into São Luís, Brazil, the coastal breezes begin to pick up, with the average wind speed reaching 6.0 m/s (13 mph)—the highest of the year. This shift marks a notable increase from the calmer late spring and early summer months, where speeds hovered around 3.3 to 4.8 m/s. With the winds gaining momentum, September not only heralds a change in the atmosphere but invites locals and visitors alike to enjoy the invigorating coastal air. Following September, the wind remains vibrant, settling back to about 5.7 m/s (13 mph) in October, suggesting that the lively breezes of early fall are a precursor to the more moderate winds that define the months ahead. Whether it's a gentle day at the beach or a lively evening stroll, September's refreshing gusts offer the perfect backdrop to experience the rhythms of this enchanting coastal city.
Weather in Sao Luis varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Sao Luis, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January exhibit distinct weather patterns in terms of temperature and precipitation. In September, the average temperature ranges from a minimum of 26°C (78°F) to a maximum of 31°C (88°F), with relatively low precipitation of only 21 mm (0.8 in) over about 5 days, and a humidity level of 51%. In contrast, January features slightly cooler temperatures, with a minimum of 24°C (75°F) and a maximum of 29°C (85°F), but significantly higher rainfall, totaling 217 mm (8.5 in) spread across 25 days, resulting in much higher humidity at 89%. This stark difference in precipitation and humidity highlights the shift from the drier late year to the wetter summer months. For more detailed information, you can check the Sao Luis weather in January.
In comparing the weather between September and February, September typically experiences warmer temperatures, with a minimum of 26°C (78°F) and a maximum of 31°C (88°F) compared to February's range of 23°C (74°F) to 29°C (85°F). However, February is characterized by significantly higher precipitation, receiving 427 mm (16.8 in) over 27 days, unlike September's milder total of 21 mm (0.8 in) across just 5 days. Additionally, February's humidity levels are notably higher at 90%, compared to September's more comfortable 51%. For more detailed information, you can check Sao Luis weather in February.
In September, the weather is characterized by warm temperatures, with minimums around 26°C (78°F) and maximums reaching up to 31°C (88°F). The month sees relatively mild precipitation of 21 mm (0.8 in) over just 5 days, resulting in a humidity level of about 51%. In contrast, March presents a much wetter and more humid climate, with average temperatures slightly cooler at 26°C (80°F) but accompanied by a staggering 483 mm (19.0 in) of rainfall spread across 30 days, leading to humidity levels soaring to 90%. For more detailed insights, you can check Sao Luis weather in March.
September and April in Sao Luis showcase significant differences in weather patterns. In September, the temperatures are warm, with averages around 27°C (82°F) and maximums reaching 31°C (88°F), accompanied by relatively low precipitation of just 21 mm (0.8 in) over about 5 days, leading to a humidity level of 51%. In contrast, April experiences slightly cooler temperatures, with averages of 27°C (80°F) and maximums hitting 30°C (86°F), but it is marked by heavy rainfall totaling 469 mm (18.5 in) across 29 days, resulting in high humidity levels of 92%. For more details, you can check out Sao Luis weather in April.
In comparing the weather of September and May, it's evident that September tends to be warmer and drier. With minimum temperatures around 26°C (78°F) and an average of 27°C (82°F), the month experiences relatively low precipitation of only 21 mm (0.8 in) over just five days, coupled with a humidity level of 51%. In contrast, May features slightly cooler temperatures, with a minimum of 24°C (75°F) and an average of 27°C (81°F), but it is significantly wetter, receiving 298 mm (11.7 in) of rain spread over 27 days, along with much higher humidity at 89%. This makes May feel quite different, often more humid and soggy compared to the drier, warmer conditions of September. For more detailed insights, visit Sao Luis weather in May.
When comparing the weather in September to that of June, we can see notable differences in both temperature and precipitation. September offers slightly warmer conditions, with average temperatures hovering around 27°C (82°F) and maximums reaching up to 31°C (88°F), while June's temperatures are similarly warm but slightly cooler, with maximums around 31°C (87°F). However, June experiences significantly more rainfall, with a total of 161 mm (6.4 in) spread over 26 days, compared to September's much lighter precipitation of 21 mm (0.8 in) over just 5 days. Additionally, humidity levels are notably higher in June at 79%, compared to 51% in September, making the latter feel more comfortable overall. For further details, you can check Sao Luis weather in June.
When comparing the weather in July and September, we see some notable differences. September typically features a minimum temperature of 26°C (78°F) and an average of 27°C (82°F), reaching a comfortable maximum of 31°C (88°F). In contrast, July has a slightly lower minimum temperature of 24°C (75°F) and an average temperature that also peaks at 31°C (89°F). However, July is characterized by significantly higher precipitation, with 107 mm (4.2 in) over 22 days, compared to September's milder 21 mm (0.8 in) over just 5 days. Additionally, July experiences higher humidity at 64%, while September's humidity stands at a more comfortable 51%. For a detailed look at July's climate, visit Sao Luis weather in July.
In comparing the weather between September and August, we can see that both months share similar temperature ranges, with average highs of 31°C (88°F) and lows around 26°C (78°F) for September and 24°C (76°F) for August. However, September experiences slightly less humidity at 51% compared to August's 55%. Additionally, precipitation decreases significantly in September, with only 21 mm (0.8 in) over 5 days, while August sees a higher total of 37 mm (1.5 in) across 11 days. For more details about August weather, you can check out Sao Luis weather in August.
In September, the weather is characterized by warm temperatures, with a minimum of 26°C (78°F) and an average of 27°C (82°F), peaking at a maximum of 31°C (88°F). The month sees relatively low precipitation at 21 mm (0.8 in) over about 5 days, with humidity averaging 51%.
Conversely, October experiences slightly cooler maximum temperatures, reaching up to 30°C (87°F), while maintaining the same minimum and average temperatures as September. However, it brings an increase in rainfall, totaling 29 mm (1.1 in) over 8 days, and a slight rise in humidity to 53%. For a more detailed look at the weather patterns during this month, check out Sao Luis weather in October.
In September, the weather is characterized by warm temperatures, with a minimum of 26°C (78°F) and a maximum of 31°C (88°F), averaging around 27°C (82°F). This month receives relatively low precipitation, only 21 mm (0.8 in) over 5 days, and maintains a moderate humidity level of 51%.
In contrast, November sees a slight decrease in maximum temperatures, peaking at 30°C (86°F), while the average remains at 28°C (82°F). However, it experiences a significant increase in rainfall, totaling 73 mm (2.9 in) across 12 days, resulting in higher humidity at 60%. This shift makes November feel more humid and wetter, creating a stark contrast to the drier conditions of September. For more detailed information, check out Sao Luis weather in November.
In September, the weather in Sao Luis is generally warm, with temperatures ranging from a minimum of 26°C (78°F) to a maximum of 31°C (88°F) and an average of 27°C (82°F). The month sees relatively low rainfall, with only 21 mm (0.8 in) of precipitation spread across about 5 days and moderate humidity at 51%. In contrast, December is slightly cooler, with temperatures ranging from a minimum of 24°C (75°F) to a maximum of 30°C (87°F), maintaining the same average of 27°C (82°F). However, December experiences significantly higher rainfall, totaling 117 mm (4.6 in) over approximately 23 days, leading to much higher humidity levels at 78%. For more details on the December conditions, you can visit Sao Luis weather in December.
As September unfolds in Sao Luis, the weather offers a delightful transition into the warmer months. The maximum temperatures rise comfortably, averaging around 27°C, setting the stage for pleasant days. Compared to the preceding months, the humidity levels dip to a manageable 51%, providing a refreshing break from the heavier rainfalls typical of earlier in the year. While there are still occasional showers—about five days of light rain resulting in just 21 mm of precipitation—the overall climate becomes sunnier and more inviting. For those interested in understanding the weather patterns in greater detail, visit Sao Luis Climate.