September Weather in Guarulhos, Brazil

Last updated: August 21, 2025

September in Guarulhos, Brazil showcases a dynamic climate characterized by a maximum temperature soaring to 34°C (94°F), while the average settles comfortably at 20°C (68°F). As the month progresses, temperatures can dip to a minimum of 9°C (48°F), highlighting the seasonal transition. With approximately 47 mm (1.9 in) of rainfall spread across 6 days, the month maintains a humidity level of 58%, contributing to a refreshing atmosphere. Overall, September in Guarulhos serves as a blend of warmth and occasional rain, perfect for those seeking to experience the beauty of Brazilian spring.

September Temperature in Guarulhos

In September, Guarulhos experiences a delightful transition as winter gives way to a warmer spring. With minimum temperatures averaging around 9°C (48°F) and an increase in daily highs reaching up to 34°C (94°F), the city witnesses a notable uptick in warmth. The average temperature of 20°C (68°F) reflects a more comfortable climate, inviting both locals and visitors to embrace outdoor activities and festivities. As the days grow longer and sunshine becomes a more prominent feature, the contrast with the chill of the preceding winter months is palpable, signaling a vibrant shift and the promise of more pleasant weather to come.

September Weather in Guarulhos: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Guarulhos, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Guarulhos, 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).
JanFebMarAprMayJunJulAugSepOctNovDec737272686464626368696871
Data source: Temperature data for Guarulhos generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Guarulhos

In September, Guarulhos experiences a slight dip in precipitation, with 47 mm (1.9 in) of rain recorded over 6 days. This marks a continuation of the trend from the drier months of July and August, where rainfall was significantly lower compared to the peak rainy season earlier in the year. As the city transitions into October, the precipitation begins to rise again, suggesting a reawakening of the wet season. The pattern showcases Guarulhos’ distinct seasonal shifts, where September serves as a brief respite from the heavier rains, providing an opportunity for both the city’s flora and residents to prepare for the impending wetter months ahead.

September Precipitation Trends in Guarulhos

The chart displays monthly precipitation patterns in Guarulhos, 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 Guarulhos, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec192166148585648296447135126150
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Guarulhos

As the year progresses in Guarulhos, September marks a noticeable shift in humidity levels, dipping to 58%, the lowest point since early summer. This decline from the 88% humidity experienced in January and February not only signals a welcome relief from the sultry heat but also indicates the gradual transition towards the drier months of the year. Following the peak humidity of 88% in the first half of the year, the trend consistently shows a decrease, culminating in the refreshing conditions of September. As October approaches, humidity further declines to 50%, suggesting that residents can expect a substantial change in the climate, setting the stage for a more comfortable atmosphere in the months to come.

September Average Humidity in Guarulhos

This chart illustrates the average monthly humidity levels in Guarulhos, 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 Guarulhos is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%88%88%84%79%77%72%65%58%50%75%80%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Guarulhos

In September, Guarulhos, Brazil, experiences a UV Index of 11, categorized as extreme, with a burn time of just 10 minutes. This marks a slight increase compared to August's very high index of 9, indicating that as spring approaches, the sun's intensity is ramping up. The trend for the year reveals that Guarulhos typically faces extreme UV levels during the first half of the year, with the UV Index peaking at 16 in January. Although UV levels dip to a high of 6 in June, they quickly rebound, illustrating the importance of sun protection as the seasons change. For further details and daily updates, you can visit Guarulhos UV Index.

Maximum UV Index Levels in Guarulhos for September

The chart shows the monthly maximum UV Index (UVI) for Guarulhos 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 Guarulhos typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec16151211867911131415
Data source: Guarulhos 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 Guarulhos

In September, Guarulhos, Brazil, basks in approximately 290 hours of sunshine, a delightful continuation of the vibrant solar trend observed throughout the year. As the transition from winter to spring unfolds, sunshine hours in September reflect a substantial uptick from the cooler months, such as June with 258 hours and August with 264 hours. This gradual increase has been a hallmark since the beginning of the year, peaking in December with a radiant 318 hours. The overall pattern highlights a clear seasonal progression, where the city experiences longer and brighter days, enhancing the allure of outdoor activities and cultural events as the warm weather approaches.

Monthly Sunshine Duration in Guarulhos: September Highlighted

The September sunshine duration represents the total number of hours Guarulhos 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.
JanFebMarAprMayJunJulAugSepOctNovDec251h267h305h293h281h258h289h264h290h273h295h318h
Data source: Guarulhos September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Guarulhos During September

In Guarulhos, Brazil, September offers a promising 42% chance of sunny weather, making it one of the better months for those seeking a bit of brightness after the winter. As the seasons transition, the likelihood of sunshine begins to wane in October with only a 14% chance, highlighting September's role as a pivotal month with improved weather relative to the preceding winter months. The upward trend from the cooler months of winter, like July and August, further emphasizes September's appeal, surpassing both with nearly as much sun as seen in April at 40%. It’s a time when the warmth starts nudging back into daily life, making it a lovely month for outdoor activities and enjoying the reawakening of spring.

Percentage of Sunny Days in September in Guarulhos

The chart illustrates the percentage of sunny days in Guarulhos 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 Guarulhos experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec13%35%36%40%35%35%55%48%42%14%33%31%
Data source: Guarulhos September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Guarulhos in September

In Guarulhos, Brazil, the rhythm of daylight shifts gracefully throughout the year, reflecting the changing seasons. September marks a transitional period where daylight sustains at 11 hours, similar to August. As the year progresses into the spring months, a gradual increase in daylight can be anticipated, peaking in December and January with 13 hours of sunlight. This trend illustrates a slow yet steady increase in daylight as the city moves from the cooler months of winter, where daylight dips to around 10 hours from May to July, back towards the vibrant and sunlit days of summer. Overall, this captivating cycle of daylight duration not only enhances the city's landscape but also enriches the daily lives of its inhabitants.

Average Daylight Hours in Guarulhos for September

The chart illustrates the variation in daylight duration in Guarulhos throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec13h 22m12h 51m12h 11m11h 30m10h 57m10h 41m10h 50m11h 19m11h 57m12h 38m13h 14m13h 32m
Data source: Guarulhos daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Guarulhos

As September arrives in Guarulhos, Brazil, the wind begins to pick up, with average speeds reaching 3.1 m/s (7 mph). This increase marks a noticeable trend; compared to the preceding months, September experiences a gentle yet invigorating breeze that hints at the changing seasons. Following a gradual rise from August's 3.0 m/s (7 mph), the winds in September are not just a subtle nudge toward the coming spring but also a prelude to October's stronger gusts, which average 3.5 m/s (8 mph). This progression reflects the city's dynamic climate, as the winds gain momentum and prepare to sweep through the landscape, enhancing the vibrant atmosphere of the month.

Average September Wind Speed in Guarulhos

The chart displays monthly wind speed patterns in Guarulhos, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.32.32.02.62.52.32.53.03.1 m/s3.53.32.9
Data source: Guarulhos September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Guarulhos Compares to Other Months

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

When comparing the weather in September and January, several notable differences emerge. September experiences a wider temperature range, with minimums around 9°C (48°F) and maximums reaching up to 34°C (94°F), while January tends to have milder lows of 15°C (59°F) and highs that peak at 33°C (91°F). Additionally, January is significantly wetter, with a precipitation total of 192 mm (7.6 in) over 19 days, compared to September's 47 mm (1.9 in) across just 6 days. The humidity levels also rise in January, averaging at 88%, contrasted with September's more comfortable 58%. For more details on weather specifics, check Guarulhos weather in January.

September and February present distinct weather patterns, reflecting the transition from late winter to early spring in the southern hemisphere. In September, temperatures range from a comfortable minimum of 9°C (48°F) to a maximum of 34°C (94°F), with an average of 20°C (68°F). The month experiences moderate precipitation of 47 mm (1.9 in) over about 6 days and a humidity level of 58%. In contrast, February showcases a warmer climate, with minimum temperatures starting at 15°C (59°F) and peaking at 34°C (93°F), averaging around 22°C (73°F). However, it brings significantly more rain, totaling 166 mm (6.5 in) across approximately 18 days, coupled with higher humidity at 88%. This stark difference illustrates the wetter and more humid conditions typically experienced in February compared to the drier September weather. For more details, check out Guarulhos weather in February.

September and March present contrasting weather patterns. In September, temperatures range from a minimum of 9°C (48°F) to a maximum of 34°C (94°F), with an average of 20°C (68°F) and relatively low precipitation of 47 mm (1.9 in) over just 6 days. The humidity stands at a moderate 58%. In contrast, March features warmer temperatures, with a minimum of 14°C (57°F) and a maximum of 32°C (90°F), averaging 22°C (73°F). March is also notably wetter, receiving 147 mm (5.8 in) of rain spread across 18 days, and has a higher humidity level of 87%. For more detailed information, check out Guarulhos weather in March.

When comparing the weather in September and April, both months have similar average temperatures, hovering around 20°C (68°F). However, September offers a wider temperature range, with highs reaching up to 34°C (94°F), while April's maximum temperature is slightly lower at 31°C (88°F). In terms of precipitation, April is wetter, with 58 mm (2.3 in) over 9 days compared to September's 47 mm (1.9 in) over just 6 days. Additionally, April experiences higher humidity levels at 84%, which can make the days feel warmer and more uncomfortable compared to September's 58% humidity. For more detailed insights, you can check Guarulhos weather in April.

When comparing the weather in September and May, we observe distinct differences in temperature and humidity. September experiences warmer temperatures, with averages around 20°C (68°F) and highs reaching up to 34°C (94°F), while May has a slightly cooler average of 18°C (65°F) and a maximum of 29°C (84°F). Additionally, September has a lower humidity level at 58%, compared to May's higher humidity of 79%. Precipitation is also a factor, with September receiving 47 mm (1.9 in) of rain over 6 days, while May sees a bit more, totaling 56 mm (2.2 in) over 7 days. For more details on May’s weather conditions, you can visit Guarulhos weather in May.

September and June exhibit distinct weather characteristics. In September, temperatures range from a minimum of 9°C (48°F) to a maximum of 34°C (94°F), with an average of 20°C (68°F), while June sees a narrower temperature range, with a minimum of 7°C (45°F) and a maximum of 28°C (82°F), averaging 18°C (64°F). Both months experience similar precipitation levels, around 47-48 mm (1.9 in), but September has slightly fewer rainy days at 6 compared to June's 7 days. Additionally, September enjoys lower humidity at 58%, contrasting with June's higher humidity of 77%. For more detailed insights on June weather in Guarulhos, check out Guarulhos weather in June.

In comparing the weather of September and July, we see a notable increase in temperatures. September boasts a minimum of 9°C (48°F), an average of 20°C (68°F), and a maximum reaching 34°C (94°F), while July’s temperatures range from a minimum of 2°C (35°F) to a maximum of 29°C (84°F), with an average of 16°C (62°F). Additionally, September experiences slightly more precipitation at 47 mm (1.9 in) over 6 days, compared to July's 29 mm (1.1 in) over just 3 days. Humidity levels are also higher in July at 72%, whereas September maintains a more comfortable 58%. For further details, you can explore Guarulhos weather in July.

In comparison to August, September experiences slightly warmer temperatures, with a minimum of 9°C (48°F) and an average of 20°C (68°F) compared to August's minimum of 5°C (42°F) and average of 17°C (63°F). The maximum temperature also rises in September, reaching 34°C (94°F) versus 31°C (89°F) in August. However, September has less precipitation, totaling 47 mm (1.9 in) over 6 days, compared to August's 64 mm (2.5 in) over 8 days. Additionally, humidity decreases from 65% in August to 58% in September, making September feel somewhat drier overall. For more detailed information, you can visit Guarulhos weather in August.

In September, the weather features a pleasant average temperature of 20°C (68°F), with daytime highs reaching up to 34°C (94°F) and nighttime lows dipping to 9°C (48°F). The month experiences moderate precipitation, totaling 47 mm (1.9 in) over six days, along with a humidity level of 58%.

As October arrives, the temperatures remain similar, with an average of 20°C (69°F), though the maximum can climb to 36°C (97°F) and the minimum rises to 12°C (53°F). However, October is much wetter, seeing 135 mm (5.3 in) of rainfall over 16 days, while humidity decreases slightly to 50%. For more details, you can check out Guarulhos weather in October.

In comparing the weather between September and November, we see some notable differences. September experiences a minimum temperature of 9°C (48°F) and an average of 20°C (68°F), while November shows a slightly higher minimum temperature of 11°C (52°F), with the same average temperature of 20°C (69°F). Both months can reach a maximum of 34°C (94°F), making the warmest days comparable. However, November is significantly wetter, with precipitation totaling 126 mm (5.0 in) over 16 days, compared to September’s 47 mm (1.9 in) over just 6 days. Additionally, humidity increases from 58% in September to 75% in November, contributing to a more muggy atmosphere during the latter month. For more detailed weather information, check out Guarulhos weather in November.

In September, the weather is generally warmer, with average temperatures ranging from a mild 9°C (48°F) to a maximum of 34°C (94°F). The month experiences lower precipitation, totaling 47 mm (1.9 in) over just 6 days, resulting in a relatively comfortable humidity of 58%.

In contrast, December sees slightly higher average temperatures, with minimums at 12°C (54°F) and maximums reaching 33°C (92°F). However, the month is significantly wetter, receiving 150 mm (5.9 in) of rainfall spread over 22 days, which raises the humidity to a more oppressive 80%. For a detailed look at December weather, visit Guarulhos weather in December.

Compare Guarulhos's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Guarulhos

As September rolls in, Guarulhos experiences a delightful transition into spring, characterized by warmer days and cooler nights. With temperatures peaking at 34°C (94°F) and dipping to a refreshing 9°C (48°F), the month showcases a unique blend of warmth and chill that sets it apart from the harsher extremes of winter and summer. The rain is moderate, with precipitation occurring on a handful of days, resulting in a humidity level that hovers around 58%. This balanced weather makes September a fantastic time for outdoor activities, allowing residents and visitors alike to enjoy the lush florals blooming across the region. For a deeper dive into the year-round climate patterns of this vibrant city, explore Guarulhos Climate.