Last updated: January 18, 2025
Viana do Castelo, Portugal, is characterized by a Csb Köppen-Geiger climate classification, which signifies a temperate maritime climate with mild summers and cooler winters. The region experiences a remarkable temperature range, with minimum readings dipping to -5°C (24°F) in January, while average temperatures hover around a comfortable 14°C (58°F). The summer months can bring significant warmth, peaking at a maximum of 37°C (99°F) in August. This climatic balance provides a unique environmental backdrop, influencing local ecology and human activities throughout the year.
Viana do Castelo experiences distinct seasonal temperature patterns, with winter months characterized by cold conditions, including January's lows reaching -5°C (24°F). As the year progresses into spring, temperatures gradually rise, showcasing a notable warming trend; March and April witness increasing averages from 11°C (52°F) to 13°C (55°F) and maximums reaching up to 27°C (80°F). By summer, the region boasts significantly warmer weather, with July and August peaking at maximum temperatures of 35°C (94°F) and 37°C (99°F), respectively, while maintaining pleasant average temperatures around 20°C (68°F). The transition to autumn sees a gradual decline, with temperatures starting to cool down again, particularly in November and December, as averages return to approximately 10°C (51°F). This seasonal cycle underscores Viana do Castelo's maritime climate, offering a dynamic range of temperatures that reflects both the coastal influences and the natural rhythm of the year.
Ponte de Lima experiences a wide temperature range, with a minimum of -4°C (26°F) in January and a maximum of 37°C (99°F) in August, making it the warmest of the three locations. In contrast, Valenca has a minimum temperature of 0°C (32°F) in January and reaches a maximum of 31°C (87°F) in August, suggesting a milder climate. Meanwhile, Viana do Castelo sees temperatures ranging from -1°C (31°F) in January to a maximum of 32°C (90°F) in August. For more detailed information, you can explore the monthly temperatures in Ponte de Lima, Valenca, and Viana do Castelo through the following links: monthly temperatures in Ponte de Lima, monthly temperatures in Valenca, and monthly temperatures in Viana do Castelo.
Viana do Castelo sees a pronounced seasonal variation in precipitation, with the winter months generally experiencing the highest rainfall. December is notably the wettest month, receiving approximately 249 mm (9.8 in) of rain over an average of 16 days, followed closely by November at 213 mm (8.4 in) across 14 days. February and March also contribute significantly to the winter precipitation totals, with February averaging 185 mm (7.3 in) and March slightly higher at 189 mm (7.4 in). This sustained precipitation during the colder months highlights the region's vulnerability to damp and chilly weather conditions, influencing both local agriculture and day-to-day life.
As the year progresses into spring and summer, the precipitation levels markedly decline. May marks the start of this trend with a decrease to 108 mm (4.2 in), followed by a significant drop in June to just 65 mm (2.6 in). July and August are particularly dry, with average monthly rainfall plummeting to 29 mm (1.1 in) and 30 mm (1.2 in), respectively, indicating the shift to sunnier and more stable weather. By September, precipitation begins to rise again, signaling the transition back into the wetter months. This seasonal pattern establishes Viana do Castelo as a region with dynamic rainfall distribution, which contributes to its lush landscapes and rich biodiversity, particularly during the wetter seasons.
Viana do Castelo experiences a clear seasonal trend in sunshine duration, with a marked increase from the winter months to the summer peak. January, often the gloomiest month, records only 158 hours of sunshine, gradually improving to 210 hours in February and reaching 286 hours by March. This gradual ascent continues through spring, where April brings an impressive 342 hours, and May typically offers even more, with 400 hours of sunlight. The onset of summer showcases Viana do Castelo basking in its sunniest period, reaching its zenith in July with 426 hours of glorious sunshine, followed by August, which remains fairly bright at 395 hours.
As summer wanes, however, a notable decline in sunshine hours occurs, signaling the transition into autumn. September sees a reduction to 343 hours, and this trend continues into October with 300 hours. By November, the average plummets to just 209 hours, and December sees a further drop to 181 hours. This pattern reveals not only the seasonal fluctuations in sunlight but also how Viana do Castelo's climate fosters a vibrant summer atmosphere while preparing for the more subdued and darker months ahead. Understanding these trends allows residents and visitors alike to plan their activities to make the most of the abundant sunshine during the summer months.
In Viana do Castelo, the UV Index exhibits significant seasonal variability, indicating a well-defined pattern of sun exposure and potential risks associated with ultraviolet radiation. The year begins with lower UV levels in January, at an index of 2, which is categorized as low, allowing for approximately 45 minutes of sun exposure before skin damage occurs. As February approaches, the UV Index rises to 4, marking a transition to moderate exposure with a reduced burn time of 30 minutes. This trend continues into March, where the index reaches a high 6, further emphasizing the need for increased sun protection as spring progresses, with a burn time of just 25 minutes.
The months of April and May experience a dramatic rise in UV Index values, peaking at an extreme level of 11 in June, which necessitates strict sun precautions due to a burn time of only 10 minutes. July and August remain in the very high category with indices of 10 and 9, respectively, while September witnesses a slight decrease back to 8. As autumn sets in, the UV levels decline again, dropping to a high of 6 in October and reverting to moderate levels by November. By December, the cycle completes as the UV Index returns to 2, signaling low exposure risks. This yearly progression highlights the importance of being aware of UV levels throughout the seasons, particularly during the peak summer months when sun safety is crucial.
UV Risk Categories
In Viana do Castelo, daylight duration exhibits a pronounced seasonal cycle, reflecting the changing position of the sun throughout the year. January brings only 9 hours of daylight, indicating the shorter days typical of winter. This incrementally increases to 10 hours in February and reaches 11 hours by March, signaling the gradual approach of spring. April continues this trend with a notable jump to 13 hours, while May offers a lengthy 14 hours of daylight, culminating in June when residents enjoy the longest days of the year at 15 hours.
As summer transitions to autumn, daylight gradually begins to decline. July still retains a generous 14 hours of light, but by August, this decreases to 13 hours. September sees further reduction to 12 hours, followed by a return to 11 hours in October. As the year draws to a close, November and December again reflect shorter daylight periods, each providing only 9 hours. This cyclical variation underscores the natural rhythm of light in Viana do Castelo, influencing daily life and outdoor activities within the region across the seasons.
Ponte de Lima, Portugal, experiences a temperate climate characterized by mild winters and warm summers. January sees minimum temperatures around -4°C (26°F) and average rainfall of 147 mm, while July boasts highs of 35°C (94°F) with minimal precipitation (34 mm). The region enjoys abundant sunshine, peaking in July with 427 hours. Fall months like October and November bring significant rain, with November receiving 228 mm, yet the overall annual average maintains a diverse climate appeal. For more detailed information, visit Ponte de Lima climate.
Valença, Portugal experiences a moderate climate characterized by warm summers and mild winters. Average temperatures range from 9°C (49°F) in January to 19°C (67°F) in July, peaking at 31°C (87°F) in August. Precipitation is highest from November to March, with December seeing around 243 mm (9.6 in) of rainfall, while July and August are the driest months. The region enjoys abundant sunshine, particularly in the summer, with July averaging 426 hours of sun. For more detailed information, visit Valenca climate.
Viana do Castelo, Portugal, experiences a temperate maritime climate characterized by mild winters and warm summers. January sees average temperatures around 9°C (49°F) with significant precipitation, peaking in November and December with over 200 mm of rain. The region enjoys maximum sunshine from May to July, with July boasting an average of 427 hours. Overall, Viana do Castelo offers a pleasant climate ideal for outdoor activities, especially during the summer months. For more details, visit Viana do Castelo climate.
In conclusion, Viana do Castelo experiences a diverse and dynamic climate characterized by significant seasonal variations in temperature, precipitation, sunshine duration, UV index, and daylight hours. The coastal region enjoys mild winters and warm summers, with a distinct transition marked by increased sunshine and UV exposure during the warmer months. Understanding these climatic patterns is essential for residents and visitors alike, as they can guide activities, tourism, and lifestyle choices throughout the year. By appreciating the interplay of these factors, one can better enjoy and navigate the unique environmental offerings of this beautiful Portuguese destination.