Viana do Castelo Weather in August
During August, Viana do Castelo experiences high daytime temperatures of 24°C (75°F) and cooler nights around 16°C (61°F). As part of the summer season, some rainfall is to be expected.
Rainfall in Viana do Castelo in August
You can expect rain on roughly 7 days based on historical data, averaging 41 mm (1.6 in) for the month. Rain days are few and the total is low, so this is a largely dry month. Any showers that do occur tend to be brief.
Temperature in Viana do Castelo in August
August is a good time to be in Viana do Castelo. Days are perfect, reaching 24°C (75°F), with nights around 16°C (61°F). During August, the summer season is in full swing. Conditions stay fairly consistent through the month, making it easier to plan what to wear. At 16°C (61°F) overnight, it can feel quite a bit cooler after dark. Worth packing something warmer for evenings, but the cooler temperatures are ideal for sleeping. On average, it is the month with the highest temperature of the year.
Sunshine in Viana do Castelo in August
There are approximately 295 hours of sunshine this month, resulting in mostly clear days.If your ideal day consists of dry skies and pleasant temperatures, June, July, August and September typically offer the best circumstances for Viana do Castelo.
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 August
Min Temperature
16°C (61°F)
Max Temperature
24°C (75°F)
Chance of Rain
22%
Precipitation
41 mm (1.6 in)
Rainy days
7 days
Humidity
73% *
Sunshine
295 hours *
Percentage Sunshine
73% *
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Viana do Castelo typically stay consistent throughout August, with daily highs averaging around 24°C (75°F). Nights are pleasant, with lows around 15°C (59°F).
Average temperatures in August
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 August
Historical weather for Viana do Castelo in August
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 August
The extremes listed below come from historical weather data collected in Viana do Castelo from 1976 through 2025.
- The hottest August day on record in Viana do Castelo reached 39°C (102°F) (August 7, 2003).
- Viana do Castelo experienced its chilliest August day on August 19, 1977, reaching only 17°C (63°F).
- The lowest overnight temperature recorded in August was 7°C (45°F) (August 26, 1985).
Best Places in Portugal in August
Find out more about the weather in Portugal and which places have the best travel conditions in this month. See all of Portugal in August →
perfect weather
pleasant
tolerable
unpleasant
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What to Wear in Viana do Castelo in August
Pleasant temperatures in August mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Rain gear is recommended, you can expect wet weather on multiple days. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.What To Do in Viana do Castelo in August
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.
