Viana do Castelo, on Portugal’s lush northern coast, enjoys a warm-summer Mediterranean climate with mild, rainy winters and pleasantly warm, dry summers. The city is known for its abundant rainfall, gentle Atlantic breezes, and ample sunshine. With moderate seasonal changes and vibrant green landscapes, Viana do Castelo is a charming destination for travellers year-round.
The best times to travel section shows how the months compare for a visit, so you can find the time of year that fits what you want to do.
Background colours of the months:
The colour shows the typical temperature: yellow (hot), green (mild) and blue (cold). How strong the colour is shows the travel season: full colour means high season, soft colour means shoulder season and soft-striped means off season.
Weather symbols:
Each month has one symbol showing what the weather is typically like, such as hot and sunny, freezing or a rainy or snowy season. Use them to quickly spot months that match the weather you want, or to avoid the ones that don't.
Crowdedness:
The people icon shows how busy the place usually is. The more people, the more crowded it gets.
Additional notes:
The grey info boxes point out special things worth knowing, like recurring weather issues or seasonal events.
Viana do Castelo’s climate is shaped by its Atlantic location and surrounding mountains, resulting in four distinct seasons and moderate temperature swings. Summers (June–September) are warm, dry, and sunny, with average highs of 23–25°C and lows of 14–16°C. July and August are the warmest and sunniest months, with more than 13 hours of daylight and up to 427 hours of sunshine per month. Rainfall is minimal in summer, averaging just 26–35 mm monthly, and humidity remains comfortable. Sea breezes from the Atlantic keep the heat pleasant, making this period ideal for beachgoers and outdoor activities.
Winters (December–February) are mild but wet, with highs of 13–15°C and lows of 7–9°C. Rainfall is frequent and heavy, especially in November and December, with monthly totals often exceeding 180–225 mm and up to 17 rainy days per month. Snow is extremely rare in the city but can occur in the nearby Serra d'Arga mountains. Despite the rain, winter days still offer 5–6 hours of sunshine. Spring (March–May) and autumn (September–November) are transitional, with mild to warm temperatures (13–21°C), moderate rainfall, and vibrant natural scenery. Winds are generally light to moderate (10–15 km/h), but can be brisk during storms, especially in winter and early spring. Annual precipitation averages 1,200–1,650 mm, and Viana do Castelo enjoys 2,300–3,600 hours of sunshine per year, supporting lush parks and gardens throughout the region.
| Average climate data for Viana do Castelo, Portugal | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Average maximum temperature (°C) | 15 | 16 | 18 | 19 | 21 | 25 | 26 | 26 | 25 | 21 | 17 | 15 | 26 |
| Average minimum temperature (°C) | 5 | 6 | 8 | 9 | 11 | 14 | 15 | 15 | 14 | 11 | 8 | 6 | 5 |
| Average water temperature (°C) | 14 | 14 | 14 | 15 | 16 | 17 | 17 | 18 | 18 | 18 | 17 | 15 | 16 |
| Average daily daylight hours (h) | 9 | 10 | 12 | 13 | 14 | 15 | 14 | 13 | 12 | 11 | 9 | 9 | 12 |
The best time to visit Viana do Castelo is from June to September, when temperatures are warmest (23–25°C), rainfall is lowest, and the city is lively with festivals, outdoor dining, and beach activities. These months offer ideal conditions for sightseeing, hiking, and enjoying the Atlantic coast, with long days and vibrant local life.
The least favourable time to visit Viana do Castelo is from November to February, when rainfall is highest, days are shortest, and cooler, damp weather can limit outdoor activities. While winters are mild compared to much of Europe, frequent rain and shorter days may restrict some plans, though the city remains peaceful and authentic.
Viana do Castelo has a warm-summer Mediterranean climate with mild, rainy winters and warm, dry summers. Rain falls year-round, with peaks in late autumn and winter. Snow is extremely rare, and the city enjoys abundant sunshine.
The best time to visit is from June to September, when the weather is warm, rainfall is low, and the city is vibrant with festivals and outdoor activities. Early autumn is also pleasant for sightseeing and fewer crowds.
Yes, Viana do Castelo is one of Portugal’s rainiest cities, with annual precipitation between 1,200 and 1,650 mm. The wettest months are November and December, while summers are much drier and sunnier.
Summer highs in Viana do Castelo typically reach 23–25°C, with July and August being the warmest months. Temperatures above 30°C are rare, and sea breezes help keep conditions comfortable.
The Atlantic is warmest from July to September, reaching 18–19°C. Swimming is possible for hardy visitors during these months, though the water is cooler than in southern Portugal.
Pack layers for cool mornings and evenings, a rain jacket for showers, and sun protection for summer. Even in summer, a jumper or light jacket is useful for breezy evenings by the sea.
Winds in Viana do Castelo are generally light to moderate, but can be brisk during storms, especially in winter and spring. The city’s coastal location means breezy conditions are common, particularly in the cooler months.
The warmest month, with the highest average maximum temperature, is August (26.3 °C). The month with the lowest average maximum temperature is January (14.7 °C). Overall, the average maximum temperature over the whole year is 20.2 °C.
The month with the highest average minimum temperature is July (15.3 °C). The coldest month, with the lowest average minimum temperature, is January (4.8 °C). Overall, the average minimum temperature over the whole year is 10.1 °C.
The month with the highest average water temperature is September (18.3 °C). The month with the lowest average water temperature is February (13.7 °C). Overall, the average water temperature over the whole year is 16.2 °C.
The month with the longest days, so the most daylight, is June (Average daylight: 15 h). The month with the shortest days, so the least daylight, is December (Average daylight: 9 h). Over the whole year there are 11.8 h of daylight per day on average.
