Last updated: February 24, 2025
Experience the vibrant September weather in Viana do Castelo, Portugal, where the maximum temperatures can reach a warm 30°C (86°F), while the average hovers around a comfortable 19°C (66°F). The minimum temperatures dip to a cool 10°C (50°F), providing a pleasant contrast. Visitors can expect about 49 mm (1.9 in) of rainfall spread over 6 days, contributing to a lush and beautiful landscape. With an average humidity of 71%, the coastal town offers a refreshing atmosphere, making it an ideal time to explore the area's rich culture and stunning scenery. Enjoy the perfect blend of warmth and refreshing breezes during your September visit!
In September, Viana do Castelo experiences a delightful transition into early autumn, with temperatures becoming pleasantly mild. The average temperature hovers around 19°C (66°F), making it a comfortable time to explore this charming coastal town. The minimum temperature settles at 10°C (50°F), while daytime highs can reach up to 30°C (86°F), blending the lingering warmth of summer with the cooler nights of fall. Compared to the preceding summer months, where highs often peaked at 32°C (90°F) in August, September's temperatures create a more inviting atmosphere for outdoor activities, strolls along the beach, or enjoying local cuisine in al fresco settings. This month marks a beautiful balance, encouraging visitors to soak in the vibrant culture and stunning landscapes of Portugal's northern coast.
September in Viana do Castelo marks a transitional month, where precipitation begins to pick up again after the drier summer. With 49 mm (1.9 in) of rainfall spread over 6 days, September serves as a gentle reminder of the wetter months ahead. While this amount is notably lower than the heavier rains experienced in winter, it indicates the onset of autumn, following the mild 30 mm (1.2 in) of August. As the region gradually shifts from the summer's warmth, September's precipitation sets the stage for the more frequent and intense rainfalls of October and November, maintaining Viana do Castelo's lush landscapes. Overall, the month encapsulates a subtle shift from the summer dryness, foreshadowing the wetter season to come.
In September, Viana do Castelo, Portugal, experiences a moderate humidity level of 71%, a slight increase from the drier months of July and August, which hovered around 63% and 64% respectively. This gradual rise in humidity signals the transition into autumn, as the summer heat begins to wane. The humidity levels in September are notably more comfortable compared to the earlier months of the year, where averages reached as high as 87% in January and 81% in February. As the region shifts towards the wetter months of October and November, with their respective humidity levels increasing to 79% and 86%, September marks a pivotal moment of change, where summer's warmth lingers just a bit longer before yielding to the cooler, damper days ahead.
As summer transitions to autumn in Viana do Castelo, Portugal, September brings a noteworthy UV Index of 7, categorizing exposure as high. This indicates a slight decrease from the peak summer months, reflecting a gradual waning of intense sunlight. With a burn time of 25 minutes, it's essential for outdoor enthusiasts to remain mindful of sun safety, even as the temperature begins to cool. The trend reveals that while the UV intensity in September is still significant, it follows the pattern of declining values after the intense August readings of 9. As the fall approaches, the UV exposure will further diminish, making September a crucial month for enjoyment of the lingering sun without neglecting skin protection. For more detailed information, visit Viana do Castelo UV Index.
UV Risk Categories
As summer wanes, September in Viana do Castelo, Portugal, offers a delightful balance of warmth and sunshine, boasting a generous 346 hours of sunlight. This marks a slight decline from the sun-drenched heights of July, which enjoys a robust 427 hours. However, it still shines brightly compared to the earlier months of the year, showcasing a steady increase in daylight from January's mere 156 hours to the peak of summer. Visitors can bask in the lingering glow of summer, with September's sun inviting leisurely afternoons along the coast and vibrant evenings exploring the town, making it a perfect time to experience the region's late-summer charm before the autumn chill sets in.
In Viana do Castelo, September brings a moderate likelihood of sunny weather, with a 43% chance of sunshine. This marks a slight dip from the peak sunny conditions of August, which enjoys a robust 66%, hinting at the waning summer. As the region transitions into autumn, the chances of clear skies begin to stabilize, reminiscent of October’s sun probability. It's worth noting that while the summer months showcase a vibrant pattern of sunny weather, September offers a balanced blend of pleasant days, making it an inviting time for outdoor activities before the cooler months arrive.
As summer transitions to autumn in Viana do Castelo, September marks a notable shift in daylight duration, offering about 12 hours of sunlight each day. This decrease follows the peak of 15 hours in June, gradually tapering off through the summer months of July and August. Observing the trend, the daylight hours begin to diminish as we prepare for the cooler months, with October set to provide 11 hours of brightness. This gradual decline highlights the changing seasons, with each month unmistakably marking the rhythm of life in this picturesque Portuguese town.
As summer gracefully transitions into autumn, September in Viana do Castelo, Portugal, welcomes a gentle breeze with an average wind speed of 3.0 m/s (7 mph)—a slight decrease from the vibrant winds of earlier months. The trend is notable as the wind gradually subsides after the summer peak, with August holding steady at 3.1 m/s. Following this pattern, October continues the trend of calmness, revealing a soothing rhythm of nature as the city prepares for the cooler months ahead. This shift not only enhances the serene atmosphere but also invites locals and visitors alike to enjoy the picturesque coastal scenery in a lighter wind embrace.
The weather in Viana do Castelo 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 Viana do Castelo and find detailed weather information for every month.
In Viana do Castelo, September typically presents a warm climate, with temperatures ranging from a pleasant 10°C (50°F) at the lowest to a maximum of 30°C (86°F), while the average temperature sits around 19°C (66°F). The month sees moderate precipitation, totaling 49 mm (1.9 in) across about 6 days, and an average humidity of 71%. In contrast, January brings significantly cooler conditions, with temperatures dipping to a minimum of -1°C (31°F) and averaging at 9°C (49°F). The maximum temperature in January reaches 20°C (69°F), but it also experiences higher precipitation levels, totaling 136 mm (5.4 in) over 10 days, accompanied by increased humidity at 87%. For more detailed insights, check out Viana do Castelo weather in January.
September and February present quite contrasting weather in Viana do Castelo. In September, temperatures range from a mild 10°C (50°F) to a warm 30°C (86°F), with an average of 19°C (66°F) and relatively low precipitation of 49 mm (1.9 in) over just six days. The humidity stands at a moderate 71%. In stark contrast, February experiences significantly cooler temperatures, with a minimum of 1°C (35°F) and a maximum of 21°C (70°F), averaging only 11°C (52°F). This month also sees much higher precipitation, totaling 185 mm (7.3 in) across 13 days, along with increased humidity at 81%. For more detailed insights, check out the Viana do Castelo weather in February.
When comparing the weather in September and March, notable differences emerge. September boasts warmer temperatures, with a minimum of 10°C (50°F) and an average high of 30°C (86°F), while March sees cooler conditions, starting from a minimum of 2°C (37°F) and reaching a maximum of 23°C (73°F). Precipitation patterns also shift significantly; September experiences relatively low rainfall of 49 mm (1.9 in) over 6 days, whereas March is much wetter, with 186 mm (7.3 in) spread across 13 days. Humidity levels are slightly higher in March at 78% compared to September's 71%. For a more detailed look at March's weather, you can check this link: Viana do Castelo weather in March.
When comparing the weather in September and April, notable differences emerge. September typically enjoys warmer temperatures with a minimum of 10°C (50°F) and an average of 19°C (66°F), peaking at 30°C (86°F). In contrast, April is cooler, featuring a minimum temperature of 3°C (38°F) and an average of 13°C (56°F), with a maximum of 26°C (79°F). Additionally, April tends to be much wetter, receiving 169 mm (6.7 in) of precipitation over 13 days, while September sees only 49 mm (1.9 in) across 6 days. The humidity levels are relatively high in both months, with April at 79% and September at 71%. For more detailed information on the weather in April, check out Viana do Castelo weather in April.
When comparing the weather in September and May, notable differences emerge. September boasts a warmer average temperature of 19°C (66°F), with maximums reaching up to 30°C (86°F), while May has a cooler average of 16°C (61°F) and maximums of 29°C (84°F). However, May experiences higher precipitation, with 106 mm (4.2 in) over about 9 days, compared to September's 49 mm (1.9 in) over 6 days. Additionally, humidity levels are slightly higher in May at 78%, compared to September's 71%. For a more detailed look at the weather specifics, you can visit Viana do Castelo weather in May.
When comparing the weather in September and June, September generally offers slightly warmer temperatures, with an average of 19°C (66°F) compared to June's average of 17°C (63°F). Both months exhibit similar humidity levels at 71%, making the air feel pleasantly warm. However, September can reach higher maximum temperatures of up to 30°C (86°F), while June peaks at 28°C (84°F). Precipitation is somewhat lighter in September, with 49 mm (1.9 in) over 6 days, compared to June's 59 mm (2.3 in) over 7 days. For a more detailed look at weather specifics, check out Viana do Castelo weather in June.
When comparing the weather in September to that of July, we see some notable differences. September has a slightly cooler average temperature, ranging from a minimum of 10°C (50°F) to a maximum of 30°C (86°F), while July's temperatures are a bit warmer, with a minimum of 11°C (53°F) and the same maximum of 30°C (87°F). Rainfall in September is higher, with 49 mm (1.9 in) over 6 days, compared to July's 26 mm (1.0 in) over just 5 days. Additionally, September experiences a higher humidity level of 71%, compared to July's 63%. For more details, check out Viana do Castelo weather in July.
In comparing the weather of September and August, September generally experiences slightly cooler temperatures with a minimum of 10°C (50°F) and an average of 19°C (66°F), compared to August's minimum of 12°C (54°F) and average of 20°C (67°F). The maximum temperature in September reaches 30°C (86°F), which is a bit lower than August's peak of 32°C (90°F). Additionally, September sees increased precipitation, with 49 mm (1.9 in) falling over 6 days, while August is relatively drier, with only 30 mm (1.2 in) over 3 days. Humidity in September also rises to 71%, compared to August's 64%. For a more detailed look at August weather, you can refer to Viana do Castelo weather in August.
September typically experiences warmer temperatures than October, with average highs reaching up to 30°C (86°F) compared to October's peak of 29°C (84°F). However, October brings a notable drop in minimum temperatures, averaging 6°C (43°F) compared to September's 10°C (50°F). Additionally, October sees a significant increase in precipitation, with 152 mm (6.0 in) over 11 days, compared to September's 49 mm (1.9 in) over just 6 days. This shift also contributes to higher humidity levels in October, which rise to 79% from September's 71%. For more detailed climate information, you can check Viana do Castelo weather in October.
September and November present stark contrasts in weather patterns. In September, temperatures are notably warmer, with a minimum of 10°C (50°F) and an average high of 30°C (86°F), making it a more comfortable month with less rainfall, totaling 49 mm (1.9 in) across just six days. Conversely, November experiences cooler temperatures, ranging from a minimum of 3°C (38°F) to a maximum of 21°C (70°F), along with significantly higher rainfall at 216 mm (8.5 in) over 15 days, contributing to a more humid environment (86%). For a closer look at November's climate specifics, check out this link: Viana do Castelo weather in November.
September and December in Viana do Castelo present a stark contrast in weather patterns. September boasts milder temperatures, with a minimum of 10°C and an average high of 30°C, making it a pleasant month for outdoor activities. In contrast, December experiences much cooler conditions, with temperatures dropping to a minimum of 2°C and an average high of just 19°C. Additionally, December sees a significant increase in precipitation, with 246 mm over 17 days compared to September's 49 mm over just 6 days, leading to a notable rise in humidity as well. For more details, you can check out Viana do Castelo weather in December.
As summer gently transitions to autumn, September in Viana do Castelo showcases a delightful shift in weather. With pleasant temperatures averaging around 19°C (66°F) and maximums peaking at 30°C (86°F), the month strikes a perfect balance between warmth and cool breezes, making it ideal for outdoor activities. Although precipitation decreases to just six days of rain, the humidity remains moderate at 71%, ensuring that the landscape retains its lush charm. This month presents a unique opportunity to enjoy the last whispers of summer while embracing the refreshing onset of fall. For more insights on weather patterns, explore Viana do Castelo Climate.