September Weather in Sao Sebastiao, Portugal

Last updated: February 24, 2025

September in São Sebastião, Portugal showcases a delightful blend of mild warmth and refreshing coastal breezes. With maximum temperatures reaching up to 24°C (76°F) and an average of 22°C (71°F), visitors can enjoy pleasant days perfect for exploration. Evenings cool off to a comfortable minimum of 19°C (66°F), making it ideal for leisurely strolls. However, this month also sees 45 mm (1.8 in) of rainfall spread over 11 days, contributing to a lush, vibrant landscape. Coupled with a high humidity level of 82%, the environment offers a unique, refreshing coastal experience, perfect for those seeking both relaxation and adventure.

September Temperature in Sao Sebastiao

In September, São Sebastião enjoys a delightful transition from the summer heat, maintaining mild temperatures that create a pleasant atmosphere for visitors. With minimums around 19°C (66°F) and averages reaching 22°C (71°F), the climate is both inviting and comfortable. The maximum temperatures can touch 24°C (76°F), making it an ideal time for outdoor activities and beach outings. This month marks a continuation of the warmer trends seen in August, yet offers a slightly softer embrace as the days gradually shorten, paving the way for the cooler autumn months ahead. It’s a perfect time to experience the beauty of this picturesque location, where warm days and cooler evenings allow for memorable exploration.

September Weather in Sao Sebastiao: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Sao Sebastiao, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec615959596265697271686462
Data source: Temperature data for Sao Sebastiao 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 Sao Sebastiao

In September, São Sebastião experiences a moderate precipitation total of 45 mm (1.8 in), mirroring the rain levels seen in August. However, the number of rainy days sees a rise to 11, suggesting a slightly wetter month despite the same overall total. This consistency in rainfall, contrasted by the transition to the drier summer months, indicates that September acts as a bridge between the warm, sun-soaked days of summer and the upcoming, wetter autumn. As the landscape begins to shift, the increased moisture helps to rejuvenate the lush greenery for which the region is renowned, making it a beautiful time for both locals and visitors alike.

September Precipitation Trends in Sao Sebastiao

The chart displays monthly precipitation patterns in Sao Sebastiao, 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.
JanFebMarAprMayJunJulAugSepOctNovDec78785077513920454583106122
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Sao Sebastiao

September in São Sebastião, Portugal, ushers in a subtle shift in humidity, settling at a comfortable 82%. As summer draws to a close, this month mirrors the lighter humidity levels seen in August, suggesting a gradual transition towards drier autumn air. Notably, the humidity throughout the year remains relatively high, with January and July peaking at 84% and 86%, respectively. This consistent moisture, especially in the first half of the year, contrasts with the lower levels in October and November, which dip to 79% and 80%. Thus, September serves as a bridge, maintaining lush atmospheric comfort while hinting at the forthcoming seasonal changes.

September Average Humidity in Sao Sebastiao

This chart illustrates the average monthly humidity levels in Sao Sebastiao, with September's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how September's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec84%83%84%84%83%84%86%82%82%79%80%85%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Sao Sebastiao

As September rolls into São Sebastião, Portugal, the sun continues to shine brightly, bringing a very high UV Index of 9. This marks a slight decline from the peak summer months of June to August, when the Index reached its highest at 10 and even 11. However, the need for sun protection remains paramount, with a burn time of just 15 minutes for unprotected skin. It's evident that the summer's intensity lingers into early autumn, so residents and visitors should remain vigilant. To better understand and prepare for UV exposure in this beautiful coastal town, check out the detailed information at Sao Sebastiao UV Index.

Maximum UV Index Levels in Sao Sebastiao for September

The chart shows the monthly maximum UV Index (UVI) for Sao Sebastiao 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.
JanFebMarAprMayJunJulAugSepOctNovDec3579101110109743
Data source: Sao Sebastiao 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 Sao Sebastiao

As summer gracefully transitions into autumn, September in Sao Sebastiao, Portugal, continues to bask in the warmth of the sun, boasting an impressive 317 hours of sunshine. This month stands as a delightful peak in the post-summer glow, following the sun-drenched July, which recorded a high of 380 hours. While the days begin to shorten, September maintains a generous amount of sunshine compared to the earlier months, reflecting an alluring charm that keeps visitors enchanted. The gradual decline in sunlight hours towards October, which sees 266 hours, hints at the approach of cooler weather, but the lingering brightness of September ensures it remains a cherished time of year for both locals and travelers alike.

Monthly Sunshine Duration in Sao Sebastiao: September Highlighted

The September sunshine duration represents the total number of hours Sao Sebastiao 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.
JanFebMarAprMayJunJulAugSepOctNovDec147h204h261h290h336h353h380h357h317h266h205h194h
Data source: Sao Sebastiao September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Sao Sebastiao During September

As summer transitions to autumn, September in São Sebastião offers a 39% chance of sunny weather, making it one of the more favorable months for enjoying the outdoors. This is a slight dip from the peak of 51% in August, but still marks a notable improvement when compared to the winter months, which see chances as low as 22% in January. The trend reveals that the region enjoys a gradual increase in sunshine from the start of the year, culminating in vibrant summer days, followed by a gentle decrease into fall. With relatively mild temperatures and pleasant chances for sun, September remains an appealing time to explore this picturesque coastal town.

Percentage of Sunny Days in September in Sao Sebastiao

The chart illustrates the percentage of sunny days in Sao Sebastiao 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 Sao Sebastiao experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec22%27%27%30%32%44%41%51%39%32%26%31%
Data source: Sao Sebastiao September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Sao Sebastiao in September

In September, São Sebastião, Portugal, enjoys approximately 12 hours of daylight, marking a gentle transition from the vibrant summer months. Following a peak in May, June, and July with 14 hours of sun, the daylight begins to wane as autumn approaches. This gradual decrease continues in October with 11 hours, and further to 10 hours in November. The pattern reflects a rhythmic shift in the seasons, where the long, sun-soaked days of summer give way to the soft, golden light of autumn, inviting residents and visitors alike to relish the lingering warmth before the shorter days of winter settle in.

Average Daylight Hours in Sao Sebastiao for September

The chart illustrates the variation in daylight duration in Sao Sebastiao throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 47m10h 45m11h 58m13h 13m14h 17m14h 48m14h 31m13h 35m12h 23m11h 8m10h 3m9h 29m
Data source: Sao Sebastiao daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Sao Sebastiao

As the summer wanes, September in São Sebastião, Portugal, continues to embrace the gentle ocean breezes, with an average wind speed of 6.3 m/s (14 mph). This month shows a subtle increase compared to the lower winds of June and August, suggesting a pleasant shift as we transition into autumn. The trend of decreasing wind speeds from the blustery heights of January and February, which average around 10.4 m/s (23 mph) and 11.1 m/s (25 mph), highlights a seasonal ebb that creates a more inviting environment for outdoor activities. As the region moves towards October, where winds slightly pick up again to 6.6 m/s (15 mph), September stands out as a serene time, perfect for enjoying the changing tides and vibrant landscapes without the overpowering gusts typical of winter's approach.

Average September Wind Speed in Sao Sebastiao

The chart displays monthly wind speed patterns in Sao Sebastiao, 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.
JanFebMarAprMayJunJulAugSepOctNovDec10.411.16.68.16.64.86.36.16.3 m/s6.68.48.9
Data source: Sao Sebastiao September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Sao Sebastiao Compares to Other Months

The weather in Sao Sebastiao changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of September's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Sao Sebastiao and find detailed weather information for every month.

September and January present contrasting weather patterns, with September generally warmer and more humid. In September, temperatures range from a minimum of 19°C (66°F) to a maximum of 24°C (76°F), with an average of 22°C (71°F). The month sees about 45 mm (1.8 in) of precipitation over 11 days and maintains a humidity level of 82%. In contrast, January has cooler temperatures, with a minimum of 11°C (52°F) and a maximum of 19°C (66°F), averaging 16°C (61°F). January experiences higher precipitation, totaling 78 mm (3.1 in) over the same number of rainy days, with humidity slightly elevated at 84%. For more details on the weather in January, visit Sao Sebastiao weather in January.

In September, the weather tends to be warmer, with temperatures ranging from a minimum of 19°C (66°F) to a maximum of 24°C (76°F), and an average of 22°C (71°F). The month typically experiences less precipitation, with about 45 mm (1.8 in) over 11 days, alongside a humidity level of 82%. In contrast, February sees cooler temperatures, with a range from 10°C (50°F) to 18°C (65°F), and an average of 15°C (59°F). This month also experiences higher precipitation, around 78 mm (3.1 in) over 14 days, coupled with slightly increased humidity at 83%. For more detailed insights, check out this Sao Sebastiao weather in February.

When comparing the weather in September and March, a clear distinction can be observed. September enjoys warmer temperatures, with averages around 22°C (71°F) and highs reaching up to 24°C (76°F), while March is cooler, averaging only 15°C (59°F) and peaking at 18°C (64°F). In terms of precipitation, both months see similar amounts, with September receiving 45 mm (1.8 in) over 11 days and March slightly higher with 49 mm (1.9 in) over 9 days. Additionally, humidity levels are quite comparable, at 82% in September and 84% in March. For those interested in exploring the weather specifics for this latter month, additional details can be found here: Sao Sebastiao weather in March.

When comparing the weather in September and April, notable differences emerge. September offers milder temperatures, with a minimum of 19°C (66°F) and a maximum of 24°C (76°F), making it quite pleasant for outdoor activities. In contrast, April experiences much cooler temperatures, ranging from a minimum of 10°C (51°F) to a maximum of 18°C (64°F), which is significantly lower than that of September.

Precipitation is also a factor, as September sees 45 mm (1.8 in) of rain over 11 days, while April has higher rainfall at 77 mm (3.0 in) over 13 days. The humidity is slightly elevated in both months, with April having 84% compared to September's 82%. For more specific insights into April weather, you can check Sao Sebastiao weather in April.

In comparing the weather of September and May, September generally offers warmer temperatures, with a minimum of 19°C (66°F) and an average of 22°C (71°F), while May is cooler, starting from a minimum of 12°C (53°F) and averaging 16°C (62°F). Despite May experiencing slightly more precipitation at 51 mm compared to September's 45 mm, the number of rainy days is similar, with 9 days in May and 11 days in September. Humidity levels are comparable, with May at 83% and September at 82%. For more detailed information, you can check Sao Sebastiao weather in May.

September and June present distinct weather characteristics. September enjoys warmer temperatures, with a minimum of 19°C (66°F) and an average of 22°C (71°F), reaching a maximum of 24°C (76°F). In contrast, June's temperatures are cooler, starting at a minimum of 14°C (58°F) and averaging 18°C (66°F), with a peak of 22°C (72°F). Precipitation levels are slightly higher in September, totaling 45 mm (1.8 in) over 11 days, compared to June's 39 mm (1.5 in) over just 6 days. Humidity rates are similar, with September at 82% and June slightly higher at 84%. For more details on June weather in this area, visit Sao Sebastiao weather in June.

When comparing the weather in September to that of July, September tends to be slightly warmer, with average temperatures reaching 22°C (71°F) compared to July's 21°C (70°F). The maximum temperature in September also exceeds that of July, at 24°C (76°F) versus 23°C (74°F). However, September experiences more precipitation, totaling 45 mm (1.8 in) over 11 days, while July has significantly less, with just 20 mm (0.8 in) over 4 days. Additionally, September has a slightly lower humidity level at 82%, compared to July's 86%. For more detailed information on July weather, you can check Sao Sebastiao weather in July.

September weather closely resembles that of August in terms of temperature, with both months featuring a minimum of 19°C (66°F), an average of 22°C (72°F), and a maximum of 24°C (76°F). However, September experiences slightly more rainfall, with precipitation occurring on 11 days, compared to just 8 days in August, while the total precipitation remains the same at 45 mm (1.8 in). Both months also share the same humidity level of 82%, making the overall feel quite consistent. For more detailed information about August weather, you can check Sao Sebastiao weather in August.

In comparing the weather conditions of September and October, we see a noticeable shift in temperature and precipitation. September boasts a milder average temperature of 22°C (71°F), with a minimum of 19°C (66°F) and a maximum of 24°C (76°F), alongside relatively low precipitation of 45 mm (1.8 in) over 11 days and high humidity at 82%. In contrast, October experiences a slight drop in the overall average temperature to 20°C (69°F), with a minimum of 15°C (59°F) and similar maximum temperatures of 24°C (75°F). However, October brings increased rainfall, totaling 83 mm (3.3 in) over 13 days, while humidity slightly decreases to 79%. For more specific details about the weather in October, you can check Sao Sebastiao weather in October.

In September, the weather typically presents warmer conditions with average temperatures around 22°C (71°F) and a maximum of 24°C (76°F), accompanied by a relatively low precipitation level of 45 mm (1.8 in) over 11 days. The humidity is notably high at 82%, making the warm days feel quite muggy. Conversely, November brings cooler temperatures, with an average of 18°C (65°F) and a minimum dipping to 13°C (55°F). This month also experiences increased rainfall, totaling 106 mm (4.2 in) over 13 days, which, combined with a slightly lower humidity of 80%, creates a more comfortable but wetter atmosphere. For more details on the weather specific to November, you can check Sao Sebastiao weather in November.

In September, the weather tends to be warmer with temperatures ranging from a minimum of 19°C (66°F) to a maximum of 24°C (76°F), accompanied by an average temperature of 22°C (71°F). The month sees moderate rainfall, totaling 45 mm (1.8 in) over about 11 days, and a humidity level of 82%. In contrast, December experiences cooler temperatures, with a minimum of 12°C (53°F) and a maximum of 20°C (68°F), leading to a lower average of 17°C (63°F). Additionally, December is wetter, receiving 122 mm (4.8 in) of precipitation over 13 days, and a slightly higher humidity of 85%. For more detailed insights on December weather, you can visit Sao Sebastiao weather in December.

Compare Sao Sebastiao's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Sao Sebastiao

As September rolls in, Sao Sebastiao transforms with milder temperatures and a hint of summer's end. The average temperature hovers pleasantly around 22°C (71°F), creating a comfortable environment for outdoor activities. Compared to the sweltering heights of summer, September offers a refreshing respite, though visitors should be prepared for some rain, as precipitation occurs on about 11 days this month. Additionally, the humidity remains relatively high at 82%, contributing to a tropical feel that is characteristic of this coastal gem. For a deeper dive into the year-round weather patterns, explore Sao Sebastiao Climate and plan your ideal getaway.