Viana do Castelo Weather in December
December in Viana do Castelo sees daytime temperatures around 15°C (59°F) and lows of 9°C (48°F) at night. Being part of the rainy season, heavy rainfall is a regular part of the day, so pack accordingly.
Rainfall in Viana do Castelo in December
As part of the rainy season, Viana do Castelo sees around 18 days of rain in December, with an average of 217 mm (8.5 in). With rain on many days and solid totals, showers are frequent and often moderately heavy. Waterproof gear is a sensible idea.
Temperature in Viana do Castelo in December
December in Viana do Castelo brings typical temperatures with highs around 15°C (59°F) and lows of 9°C (48°F). December is known for being in the winter season. Conditions are often most pleasant around the middle of the day. At 9°C (48°F) overnight, it gets properly cold after dark. On the bright side, cold nights tend to make for excellent sleeping conditions.
Sunshine in Viana do Castelo in December
With about 124 hours of sunshine, the area enjoys a nice balance of sun and rainy moments, creating a pleasant environment.December in Viana do Castelo can still be great, but if you prefer pleasant temperatures along with dry and sunny conditions, our weather planner can help you explore other options in the world.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Portugal, check out our Viana do Castelo's climate page.
Viana do Castelo Temperature in December
Min Temperature
9°C (48°F)
Max Temperature
15°C (59°F)
Chance of Rain
59%
Precipitation
217 mm (8.5 in)
Rainy days
18 days
Humidity
81% *
Sunshine
124 hours *
Percentage Sunshine
46% *
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Viana do Castelo typically stay consistent throughout December, with daily highs averaging around 15°C (59°F). Nights are cold, with lows typically ranging from 6°C (43°F) to 8°C (46°F).
Average temperatures in December
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in December
Historical weather for Viana do Castelo in December
Browse day-by-day weather records for Viana do Castelo spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Viana do Castelo historical weather extremes in December
Based on 49 years of weather observations (1976-2025), these are the most extreme conditions recorded in Viana do Castelo.
- The hottest December day on record in Viana do Castelo reached 24°C (75°F) (December 2, 1985).
- The lowest daytime temperature in December was 7°C (45°F), recorded on December 21, 2025.
- Viana do Castelo registered its coldest December night on December 25, 2001, with temperatures dropping to -5°C (23°F).
- The wettest December day on record brought 87 mm (3.4 in) of precipitation to Viana do Castelo (December 7, 2000).
Best Places in Portugal in December
Find out more about the weather in Portugal and which places have the best travel conditions in this month. See all of Portugal in December →
perfect weather
pleasant
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What to Wear in Viana do Castelo in December
The weather can swing between comfortable and chilly in December, so flexibility is key. Pack a variety of tops, at least one warm layer, and both shorts and long pants. This gives you options no matter what the day brings. It's going to pour! Pack a good poncho and prepare for very wet conditions. Bring sunglasses since you'll have some sunny periods throughout the monthWhat To Do in Viana do Castelo in December
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Portugal, check out our Viana do Castelo's climate page.
Temperature Rainfall Sunshine Humidity
See the full Viana do Castelo climate overview or explore weather in Portugal.
