September Weather in Petropolis, Brazil

Last updated: August 21, 2025

September in Petropolis, Brazil offers a vibrant blend of warm days and cool nights. With maximum temperatures reaching 35°C (95°F) and an average hovering around 21°C (71°F), this month invites outdoor exploration. However, visitors should be prepared for the occasional rainfall, as 10 days see a total precipitation of 67 mm (2.6 in), contributing to a comfortable humidity level of 68%. Whether basking in the sun or enjoying the refreshing showers, September is a month of dynamic weather that showcases Petropolis’s enchanting charm.

September Temperature in Petropolis

As the transition from winter to spring unfolds in Petropolis, Brazil, September welcomes a refreshing shift in temperatures. With minimums rising to 11°C (52°F) and average temperatures reaching a comfortable 21°C (71°F), the city begins to shake off the cool grip of the previous months. Daytime highs peak at a warm 35°C (95°F), close to the sweltering temperatures seen in the summer months ahead. This upward trend in warmth, compared to the cooler averages of July and August, hints at the vibrant energy of springtime in Petropolis, where lush landscapes and blooming flora are just around the corner.

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

The chart illustrates September temperature patterns in Petropolis, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Petropolis, 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).
JanFebMarAprMayJunJulAugSepOctNovDec777675726867656671727274
Data source: Temperature data for Petropolis generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Petropolis

In September, Petropolis experiences a noticeable uptick in precipitation, averaging 67 mm (2.6 inches) over approximately 10 rainy days. This marks a slight increase compared to the drier months of July and August, which saw only 30 mm (1.2 in) and 63 mm (2.5 in) respectively. As the season transitions from the chill of winter to the warmth of spring, rainfall begins to pick up again, hinting at the wetter months ahead. Despite September's moderate totals, it lays the groundwork for the more substantial downpours that characterize the upcoming months, notably November, when precipitation can soar to 250 mm (9.9 in). Thus, September serves as a gentle reminder of the changing climate in this lush region of Brazil, setting the stage for the vibrant growth that follows.

September Precipitation Trends in Petropolis

The chart displays monthly precipitation patterns in Petropolis, 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 Petropolis, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec212303209926445306367142250288
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Petropolis

September in Petropolis, Brazil, marks a notable shift in humidity levels as the year begins to transition into drier months. With an average humidity of 68%, September experiences the lowest levels since January, when conditions are at their most humid, averaging 85%. This gradual decline, unfolding from the summer months of high humidity, highlights the onset of more comfortable weather as the region prepares for the briskness of October with its humidity dropping further to 61%. The trend showcases a steady decrease from the peak months, creating an inviting atmosphere for both residents and visitors looking to enjoy the lush landscapes without the heaviness of summer moisture.

September Average Humidity in Petropolis

This chart illustrates the average monthly humidity levels in Petropolis, 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 Petropolis is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%85%86%83%81%80%76%73%68%61%72%75%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Petropolis

In September, Petropolis experiences a notable UV Index of 12, categorizing it as extreme with a quick burn time of just 10 minutes. This marks a shift back to maximum sun exposure after slightly lower indices in the summer months, with the UV Index peaking as high as 16 in January. As the year transitions into spring, it’s essential for residents and visitors to remain vigilant about sun safety, especially considering that the trend of extreme UV conditions persists through to November with indices reaching 14 and 15 later in the year. For further information and details on daily UV intensity, visit Petropolis UV Index.

Maximum UV Index Levels in Petropolis for September

The chart shows the monthly maximum UV Index (UVI) for Petropolis 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 Petropolis typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec16151311867912131415
Data source: Petropolis 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 Petropolis

As September unfolds in Petropolis, Brazil, the city basks in an impressive 298 hours of sunshine, marking a notable peak just before the days begin to shorten. This month not only reflects a steady warmth typical of spring, but it also showcases an upward trend compared to the previous few months, where sunshine hours hovered around the lower 270s. With daylight steadily increasing since the mid-year mark, September stands as a vibrant transitional period, hinting at the pleasant October days to come. This golden season invites residents and visitors alike to enjoy the lush landscapes and invigorating outdoor activities that Petropolis is renowned for, all under a strikingly bright sky.

Monthly Sunshine Duration in Petropolis: September Highlighted

The September sunshine duration represents the total number of hours Petropolis 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.
JanFebMarAprMayJunJulAugSepOctNovDec270h270h310h295h284h279h296h278h298h279h281h312h
Data source: Petropolis September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Petropolis During September

In Petropolis, Brazil, the likelihood of sunny weather in September offers a moderate chance, with 42% probability of sunshine. This places September in a somewhat favorable position, following the sunnier months of July (63%) and August (53%). Interestingly, as we transition from the peak of winter into early spring, the chances of clear skies dip slightly but remain above the average seen earlier in the year, with January (30%) and February (23%) showcasing notably lower probabilities. Such patterns suggest that while September may not be the sunniest month, it serves as a bridge toward more consistent sunshine as the year progresses, inviting those who enjoy moderate warmth to embrace the beauty of Petropolis’ early spring charm.

Percentage of Sunny Days in September in Petropolis

The chart illustrates the percentage of sunny days in Petropolis 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 Petropolis experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec30%24%40%43%44%50%63%53%42%14%25%30%
Data source: Petropolis September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Petropolis in September

In Petropolis, Brazil, the rhythmic ebb and flow of daylight reveal a captivating progression throughout the year. As January ushers in the longest days with 13 hours of sunlight, the duration gradually tapers to 10 hours during the cooler months of June and July. By September, the daylight extends to 11 hours, marking a subtle transition as the city approaches spring. This consistency in daylight duration during these months hints at a harmonious climate, where the shift into longer days resumes with October bringing back 12 hours of sunlight, leading into the vibrant warmth of summer by the end of the year. The pattern illustrates a delightful cycle, inviting residents and visitors alike to enjoy the enchanting shifts in Petropolis’ natural light.

Average Daylight Hours in Petropolis for September

The chart illustrates the variation in daylight duration in Petropolis throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec13h 19m12h 49m12h 10m11h 32m11h10h 45m10h 53m11h 21m11h 58m12h 36m13h 11m13h 28m
Data source: Petropolis daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Petropolis

As September arrives in Petropolis, Brazil, the breeze begins to pick up, heralding the transition into the spring season. With an average wind speed of 1.9 m/s (4 mph), September marks a notable increase from the relatively calm conditions of the earlier months. This gentle uptick not only signifies a change in the wind’s whisper but also hints at the vibrant life that spring brings. Following a steady rise throughout the winter months, from 1.6 m/s (4 mph) in July to 1.8 m/s (4 mph) in August, this increase in wind speed creates a refreshing atmosphere, perfect for outdoor exploration. The pattern reveals that as the year progresses, so does the vigor of the winds, offering both a literal and metaphorical breath of fresh air as nature awakens.

Average September Wind Speed in Petropolis

The chart displays monthly wind speed patterns in Petropolis, 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.
JanFebMarAprMayJunJulAugSepOctNovDec1.61.31.41.51.41.51.61.81.9 m/s1.71.71.6
Data source: Petropolis September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Petropolis Compares to Other Months

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

In September, the weather typically features a minimum temperature of 11°C (52°F) and an average of 21°C (71°F), with highs reaching up to 35°C (95°F). Precipitation is moderate, averaging 67 mm (2.6 in) spread over about 10 days, and humidity levels hover around 68%. In contrast, January offers warmer conditions, with minimum temperatures around 17°C (63°F) and an average temperature of 25°C (77°F), peaking at 34°C (93°F). However, it is also the wettest month, with significant rainfall totaling 212 mm (8.3 in) across approximately 18 days and higher humidity at 85%. For more detailed information about January weather, you can visit Petropolis weather in January.

September and February present distinct weather patterns. In September, temperatures range from a minimum of 11°C (52°F) to a maximum of 35°C (95°F), with an average of 21°C (71°F). The month sees an average precipitation of 67 mm (2.6 in) over about 10 days, along with a humidity level of 68%. In contrast, February is warmer, with temperatures ranging from a minimum of 18°C (64°F) to the same maximum of 35°C (94°F), but offering a higher average of 24°C (76°F). Notably, February experiences significant rainfall, with 302 mm (11.9 in) over approximately 20 days, resulting in higher humidity at 85%. For more detailed insights, check out Petropolis weather in February.

In September, the weather features a comfortable average temperature of 21°C (71°F), with daytime highs reaching up to 35°C (95°F) and lows dropping to 11°C (52°F). The month experiences moderate rainfall, totaling 67 mm (2.6 in) over about 10 days, with humidity levels around 68%. In contrast, March tends to be warmer and more humid, with an average temperature of 24°C (76°F) and highs approaching 33°C (92°F). However, it is also significantly wetter, receiving 209 mm (8.2 in) of precipitation over 21 days and higher humidity at 86%. For more details about March weather specifically, you can check Petropolis weather in March.

In September, the weather is generally warm, with temperatures ranging from a minimum of 11°C (52°F) to a maximum of 35°C (95°F), averaging 21°C (71°F). The month experiences 67 mm (2.6 in) of precipitation over about 10 days, with humidity at 68%. In contrast, April sees slightly higher temperatures, with a minimum of 13°C (56°F), an average of 22°C (72°F), and a maximum of 33°C (92°F). However, April is wetter, receiving 92 mm (3.6 in) of rainfall over 15 days, and the humidity increases to 83%. For a closer look at April's weather, check out Petropolis weather in April.

September and May exhibit striking similarities in their weather patterns, both offering mild temperatures and occasional rain. In September, the average temperature reaches around 21°C (71°F), with a maximum of 35°C (95°F) and a minimum of 11°C (52°F). The month sees about 67 mm (2.6 in) of precipitation over roughly 10 days, with humidity levels at 68%. In contrast, May has slightly cooler temperatures, with an average of 20°C (68°F), a maximum of 31°C (88°F), and a minimum of 9°C (49°F). Precipitation is comparable, with 64 mm (2.5 in) over 9 days and higher humidity at 81%. For more specific details about the weather in May, you can check Petropolis weather in May.

In comparing the weather conditions of September and June, September tends to be warmer overall, featuring an average temperature of 21°C (71°F) and a maximum of 35°C (95°F), while June has slightly cooler averages with a minimum of 10°C (50°F) and a maximum of 30°C (87°F). Additionally, September experiences a higher total precipitation of 67 mm (2.6 in) over about 10 days, compared to June's 45 mm (1.8 in) over 9 days. Humidity levels in June are somewhat higher at 80%, compared to September's 68%, suggesting that June may feel more humid and potentially uncomfortable despite the cooler temperatures. For more detailed insights on June weather, you can check out Petropolis weather in June.

In comparing the weather between September and July, September generally presents warmer temperatures, with average highs reaching up to 35°C (95°F), contrasting with July's maximum of 30°C (87°F). The minimum temperatures in September are also higher, starting at 11°C (52°F) compared to July's 7°C (45°F). Additionally, September experiences more precipitation, recording 67 mm (2.6 in) over 10 days, whereas July has only 30 mm (1.2 in) across 5 days. Interestingly, while September's humidity is slightly lower at 68%, July sees a higher humidity level of 76%. For a more detailed look at July's weather, you can visit Petropolis weather in July.

September's weather exhibits warmer temperatures compared to August, with a minimum of 11°C (52°F) and a maximum of 35°C (95°F), while August sees a cooler range from 8°C (46°F) to a maximum of 32°C (89°F). The average temperature in September is also noticeably higher at 21°C (71°F), compared to August's average of 19°C (66°F). Precipitation levels are fairly similar, with September receiving 67 mm (2.6 in) over 10 days, slightly more than August's 63 mm (2.5 in) over 9 days. Humidity remains high in both months, but slightly lower in September at 68% compared to August's 73%. For a closer look at August's weather specifics, you can check Petropolis weather in August.

In comparison to September, October experiences slightly warmer temperatures with a minimum of 13°C (56°F) and an average of 22°C (72°F), compared to September's minimum of 11°C (52°F) and average of 21°C (71°F). Both months have notable highs, with October peaking at 36°C (98°F), just one degree higher than September's maximum of 35°C (95°F). However, October brings significantly more rainfall, accumulating 142 mm (5.6 in) over 18 days, compared to September's 67 mm (2.6 in) over 10 days. Interestingly, the humidity decreases slightly in October, recorded at 61% versus September's 68%. For more details, you can visit Petropolis weather in October.

September and November display surprisingly similar temperature ranges, with both months experiencing minimum temperatures around 11°C (52°F) and maximum temperatures peaking at 35°C (95°F). However, November tends to be wetter and more humid, receiving significantly more precipitation at 250 mm (9.9 in) over 19 days compared to September's 67 mm (2.6 in) over 10 days. This increase in rainfall also leads to a slight rise in humidity, averaging 72% in November versus 68% in September. The increased precipitation and humidity in November can create a more tropical and lush atmosphere, making it a noteworthy transition month. For more detailed information, visit Petropolis weather in November.

In September, the weather is characterized by milder temperatures, ranging from a minimum of 11°C (52°F) to a maximum of 35°C (95°F), with an average of 21°C (71°F). The month sees some rainfall, with a total of 67 mm (2.6 in) over about 10 days and humidity levels at around 68%.

In contrast, December brings warmer conditions, with minimum temperatures of 14°C (57°F) and maximums reaching 33°C (92°F), averaging 24°C (75°F). However, it also experiences significantly higher precipitation, accumulating 288 mm (11.3 in) spread across approximately 24 days, and has a slightly increased humidity of 75%. For more details on December weather, you can visit Petropolis weather in December.

Compare Petropolis's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Petropolis

As September unfolds in Petropolis, the weather begins to transition, offering a pleasant blend of warmth and mildness. With temperatures gradually rising, residents and visitors alike can enjoy the average warmth that invites outdoor activities. However, this month also brings a few rainy days, contributing to a noticeably humid atmosphere that contrasts with the drier months ahead. Overall, September serves as a vibrant bridge between the cooler winter and the hotter summer, making it a unique time to experience the lush beauty of this region. For more insights on how September compares to other months, visit Petropolis Climate.