September Weather in Aveiro, Portugal

Last updated: February 24, 2025

September in Aveiro, Portugal offers a delightful climate, with maximum temperatures reaching a warm 31°C (88°F) while the average settles at a pleasant 20°C (68°F). For those who prefer cooler evenings, nighttime temperatures dip to a minimum of 11°C (52°F). This month experiences light precipitation totaling around 32 mm (1.3 in), with just four rainy days scattered throughout, making it an ideal time for outdoor adventures. Visitors will appreciate the moderate humidity level of 71%, ensuring a comfortable atmosphere to explore Aveiro's charming canals and cultural sites. Enjoy the blissful early autumn weather as the city transitions into fall.

September Temperature in Aveiro

In September, Aveiro, Portugal, transitions into a delightful early autumn, showcasing temperatures that remain quite mild. With a minimum of 11°C (52°F) and maximums reaching up to 31°C (88°F), the month delivers a comfortable average of 20°C (68°F), reminiscent of the summer's warmth. This gradual decline from the peak summer heat allows for pleasant outdoor exploration, where visitors can bask in the lingering sun without the intensity of July and August. As the month progresses, residents and tourists alike can enjoy the cooling evenings—a gentle reminder that the vibrant summer is giving way to the restful hues of autumn.

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

The chart illustrates September temperature patterns in Aveiro, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec515455586365686867635754
Data source: Temperature data for Aveiro 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 Aveiro

In Aveiro, Portugal, September marks a transition in the weather, where precipitation levels begin to pick up again after the hot summer months. With rainfall measuring 32 mm (1.3 in) over about 4 days, September serves as a precursor to the wetter autumn season that follows. This is a notable increase compared to the dry spells of July and August, during which the region only received 13 mm (0.5 in) and 14 mm (0.5 in) of rain, respectively. As the year progresses into October and November, the rain intensifies significantly, often reaching over 100 mm, indicating a shift towards the wetter months that characterize the region's climate. The gradual increase in precipitation starting in September reflects the impending changes in weather patterns, setting the stage for the lush landscapes that define Aveiro's autumn scenery.

September Precipitation Trends in Aveiro

The chart displays monthly precipitation patterns in Aveiro, 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.
JanFebMarAprMayJunJulAugSepOctNovDec771091141146432131432101137150
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Aveiro

In September, Aveiro, Portugal experiences a shift in humidity, averaging around 71%, which marks a gradual increase from the drier months of July and August, where levels dipped to 63% and 64% respectively. This subtle rise foreshadows the return of the wetter autumn months, as humidity levels begin to climb back toward the cooler months of October and November. Notably, the overall trend showcases a seasonal pattern, with summer months favoring lower humidity, while winter months consistently present higher levels, peaking at 87% in both January and December. Thus, September serves as a pivotal transition point, heralding the onset of the moist fall season in this charming coastal city.

September Average Humidity in Aveiro

This chart illustrates the average monthly humidity levels in Aveiro, 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.
JanFebMarAprMayJunJulAugSepOctNovDec87%81%78%79%78%71%63%64%71%79%86%87%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Aveiro

As summer fades, September in Aveiro, Portugal, maintains a very high UV Index of 8, making sun protection still essential for outdoor activities. The burn time remains short at just 15 minutes, emphasizing the need for vigilance even as temperatures begin to drop. This month marks a gradual decrease from the intense peaks of July and June, both hitting a UV Index of 10, but it still indicates that UV radiation remains significant for sun seekers. As you soak in the last warm rays of the season, remember to stay sun-safe! For more detailed information, check out Aveiro UV Index.

Maximum UV Index Levels in Aveiro for September

The chart shows the monthly maximum UV Index (UVI) for Aveiro 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.
JanFebMarAprMayJunJulAugSepOctNovDec24689101098642
Data source: Aveiro 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 Aveiro

As summer gracefully fades into autumn, September in Aveiro, Portugal, embraces an inviting balance of warmth and openness with 346 hours of sunshine. This delightful month continues the trend of abundant light established in the peak of summer, although it gently declines from August's 393 hours. The gradual decrease signifies the transition towards the milder hues of fall, yet September still boasts significantly more sunlight than the winter months, making it an enchanting time to explore the city's canals and colorful architecture. With a sunrise-filled sky and comfortable temperatures, the allure of Aveiro remains strong, ensuring that every visitor can bask in the golden glow of early autumn.

Monthly Sunshine Duration in Aveiro: September Highlighted

The September sunshine duration represents the total number of hours Aveiro 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.
JanFebMarAprMayJunJulAugSepOctNovDec165h215h293h347h406h407h424h393h346h303h212h192h
Data source: Aveiro September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Aveiro During September

In Aveiro, Portugal, September presents a notable shift in weather dynamics, with a 47% chance of sunny days. This month marks a transition from the peak summer sunshine observed in August, which boasts a 65% chance, as the region begins to move toward autumn's cooler embrace. While September's likelihood of sunshine is slightly lower than its summer predecessor, it still holds an appealing promise compared to the earlier months of the year, where chances often dip below 50%. With the warmth of summer lingering on, visitors can enjoy a blend of mild temperatures and a healthy dose of sunshine, making September a charming time to explore the beauty of Aveiro before the autumnal chill sets in.

Percentage of Sunny Days in September in Aveiro

The chart illustrates the percentage of sunny days in Aveiro 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 Aveiro experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec51%21%58%41%50%59%61%65%48%47%69%37%
Data source: Aveiro September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Aveiro in September

In Aveiro, Portugal, the rhythm of daylight shifts with the seasons, creating a captivating transition throughout the year. In September, the daylight extends for approximately 12 hours, providing a gentle tapering from the vibrant 14 hours of light in May and June. As summer gradually recedes, this month marks a subtle shift towards autumn, with daylight hours beginning to decline. The pattern reveals an elegant progression: starting from just 9 hours in January, the days gradually lengthen to their peak in June before transitioning back. This cyclical variation not only highlights the beauty of Aveiro's climate but also offers a perfect backdrop for enjoying outdoor activities as the days start to cool while still basking in ample sunshine.

Average Daylight Hours in Aveiro for September

The chart illustrates the variation in daylight duration in Aveiro throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 37m10h 39m11h 57m13h 18m14h 27m15h 1m14h 43m13h 42m12h 24m11h 4m9h 54m9h 18m
Data source: Aveiro daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Aveiro

As summer fades and autumn approaches, September in Aveiro ushers in a gentle breeze with an average wind speed of 3.7 m/s (8 mph). This slight dip from the previous months contrasts with the higher winds of July and August, reflecting the transition from the vibrant summer season to a more subdued fall atmosphere. The trend of diminishing wind speeds continues into October, suggesting a calm period ahead as local flora begins to change colors. Overall, September’s wind brings a refreshing touch, hinting at the cozy, tranquil days to come in this beautiful Portuguese locale.

Average September Wind Speed in Aveiro

The chart displays monthly wind speed patterns in Aveiro, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.55.33.63.24.44.54.73.93.7 m/s3.53.94.9
Data source: Aveiro September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Aveiro Compares to Other Months

The weather in Aveiro 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 Aveiro and find detailed weather information for every month.

In September, temperatures are generally warmer, ranging from a minimum of 11°C (52°F) to a comfortable average of 20°C (68°F), with highs reaching up to 31°C (88°F). The month experiences relatively low precipitation, with only 32 mm (1.3 in) over about 4 days and humidity around 71%. In contrast, January brings cooler temperatures, with a minimum of 2°C (36°F), an average of 11°C (51°F), and a maximum of 20°C (69°F). Additionally, January is wetter, receiving 77 mm (3.0 in) of rain over 8 days and higher humidity at 87%. For more details on January weather, you can check Aveiro weather in January.

September typically boasts warmer temperatures compared to February, with an average of 20°C (68°F) and maximum highs reaching 31°C (88°F), while February's average temperature is only 12°C (54°F), peaking at 21°C (70°F). Additionally, September sees less precipitation, with merely 32 mm (1.3 in) over about 4 days, whereas February experiences significantly higher rainfall at 109 mm (4.3 in) across 11 days. Humidity levels are also higher in February, sitting at 81% compared to September's 71%. For more detailed information, you can check Aveiro weather in February.

September weather is generally warmer and drier compared to March. In September, temperatures range from a comfortable 11°C (52°F) at night to a high of 31°C (88°F) during the day, with an average temperature of 20°C (68°F). This month sees only 32 mm (1.3 in) of precipitation over about four days, coupled with a humidity of 71%. In contrast, March experiences cooler temperatures, ranging from 4°C (40°F) at night to a maximum of 24°C (76°F), averaging 13°C (56°F). It is also significantly wetter, with 114 mm (4.5 in) of rain spread over approximately eleven days, and humidity levels reach 78%. For more details about the March weather, you can visit Aveiro weather in March.

When comparing the weather in September and April, it's clear that September tends to be warmer and drier. September boasts an average temperature of 20°C (68°F), with highs reaching up to 31°C (88°F), while April averages a cooler 15°C (58°F), peaking at 26°C (79°F). Additionally, September sees significantly less rainfall, with only 32 mm (1.3 in) of precipitation over just 4 days, compared to April's 114 mm (4.5 in) spread over 12 days. Moreover, April experiences higher humidity levels at 79%, compared to 71% in September. For a more detailed look at April weather, you can refer to Aveiro weather in April.

September and May present distinct weather characteristics, with September generally being warmer and drier. In September, temperatures range from a minimum of 11°C (52°F) to a maximum of 31°C (88°F), averaging around 20°C (68°F) with lower precipitation at 32 mm (1.3 in) over 4 days. In contrast, May features slightly cooler temperatures, with a minimum of 9°C (48°F) and a maximum of 30°C (87°F), averaging 17°C (63°F). Additionally, May experiences more precipitation, totaling 64 mm (2.5 in) over 8 days, and higher humidity at 78%. For a closer look at the weather specifics for May, check out Aveiro weather in May.

In comparing the weather between September and June, we see some notable differences. September typically offers a warmer average temperature of 20°C (68°F), while June has a cooler average of 18°C (65°F). Both months experience similar high temperatures, with September peaking at 31°C (88°F) and June slightly lower at 30°C (86°F). Precipitation levels are comparable, with both months receiving around 32 mm (1.3 in), but June tends to have more rainy days, averaging about 7 days compared to September's 4 days. Despite these similarities, both September and June maintain a consistent humidity level of 71%. For more detailed insights into June's climate, you can check out Aveiro weather in June.

When comparing the weather in September and July, both months share a similar average temperature of 20°C (68°F), but exhibit notable differences in their extremes. In July, temperatures range from a minimum of 13°C (56°F) to a maximum of 33°C (91°F), making it slightly warmer overall compared to September, where temperatures can dip to 11°C (52°F) and peak at 31°C (88°F). Precipitation is also more frequent in September with 32 mm (1.3 in) over 4 days, compared to July’s much lower total of 13 mm (0.5 in) over just 2 days. Additionally, September experiences higher humidity levels at 71%, while July maintains a more comfortable 63%. For a more detailed look at July's weather patterns, you can check out Aveiro weather in July.

The weather in September was slightly cooler than in August, with minimum temperatures dropping from 13°C (56°F) in August to 11°C (52°F) in September. Both months shared an average temperature of 20°C (68°F), while September's maximum temperature reached 31°C (88°F), just a degree lower than August's maximum of 32°C (91°F). Precipitation was more frequent in September, accumulating 32 mm (1.3 in) over 4 days compared to August's 14 mm (0.5 in) over just 2 days. Additionally, September experienced higher humidity at 71%, compared to August's 64%. For more detailed weather information, you can check out Aveiro weather in August.

September and October exhibit contrasting weather patterns, particularly in temperature and precipitation. September boasts a mild average temperature of 20°C (68°F), with a pleasant maximum reaching 31°C (88°F) and only 32 mm of rain over approximately 4 days. In comparison, October experiences a drop in both average temperature to 17°C (63°F) and minimum temperature to 8°C (46°F), while still hitting a peak of 31°C (87°F). However, October is notably wetter, with precipitation increasing to 101 mm (4.0 in) spread over 9 days, and humidity rising to 79%. For more detailed information, you can check Aveiro weather in October.

September and November exhibit marked differences in weather patterns. In September, temperatures range from a minimum of 11°C (52°F) to a pleasant average of 20°C (68°F) and can peak at a warm 31°C (88°F). The month sees relatively low precipitation, with only 32 mm (1.3 in) over just 4 days, and a humidity level of 71%. In contrast, November brings cooler temperatures with a minimum of 6°C (44°F), an average of 14°C (57°F), and a maximum of 23°C (73°F). This month is also considerably wetter, experiencing 137 mm (5.4 in) of precipitation across 14 days and higher humidity at 86%. For more detailed insights into November's weather, you can refer to Aveiro weather in November.

September and December present contrasting weather patterns. In September, temperatures typically range from a mild 11°C (52°F) at night to a warm 31°C (88°F) during the day, with an average temperature of 20°C (68°F). The month experiences relatively low precipitation at 32 mm (1.3 in) over just 4 days and a humidity level of 71%. In contrast, December sees a significant drop in temperature, with minimums falling to 3°C (38°F) and maximums reaching 19°C (66°F), averaging at 12°C (54°F). This month is much wetter, with precipitation totaling 150 mm (5.9 in) spread over 14 days, and the humidity rises to 87%. For more details on the December climate, you can visit Aveiro weather in December.

Compare Aveiro's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Aveiro

As summer wanes, September in Aveiro offers a delightful shift in weather, marked by pleasantly warm days and cooler nights. The transition to autumn brings an average temperature of around 20°C (68°F), making it more comfortable compared to the hotter peak summer months. While you can still expect a few sunny days, the likelihood of rain increases slightly, with about 32 mm of precipitation spread over just a handful of days. This moderate humidity level of 71% gives the air a refreshing quality, enhancing the overall experience of exploring this charming coastal city. For a detailed look at how September fits into the broader seasonal patterns, check out Aveiro Climate.