AI-generatedViana do Castelo at a glance
- Best time
- Jul – Aug
- Warmest month
- Aug · 23°
- Warmest sea
- Aug · 17.2°
- Sunshine a year
- 2,470 h
- Rain a year
- 1,405 mm
- Climate
- Maritime
- Time zone
- UTC+0 / UTC+1
- Elevation
- 12 m
Climate in Viana do Castelo
Viana do Castelo has a maritime climate with moderate summers and cool, often grey winters. August is the warmest month with average highs of 23 °C, while January is the coolest at 13 °C. With around 2,470 hours of sunshine a year, Viana do Castelo is sunny; July is the sunniest month with 10.3 hours a day.
Holiday weather through the year
Weather in October
Holiday weather in October
Poor
Best time to visit: July – August
Keep in mindFrequent rain
A typical day in October
- Morning, 08:00: about 14°
- Midday, 13:00: about 18°
- Afternoon, 16:00: about 19°
- Evening, 20:00: about 17°
- Night, 23:00: about 16°
07:4618:56
Cool evenings: pack a jumper or a jacket.
Estimated from the average high and low: coolest around sunrise, warmest in mid-afternoon.
Light for photos in October
- Golden hour
- Morning 07:29–08:24 · evening 18:18–19:13
- Blue hour
- Morning 07:18–07:29 · evening 19:13–19:24
Golden hour: the sun between 4° below and 6° above the horizon; blue hour: 6° to 4° below it. Times for the 15th of the month; mountains and clouds shift the light.
What is the weather like in Viana do Castelo in October?
In October, Viana do Castelo is mild: daytime highs average 19 °C, and nights cool down to about 14 °C. The sea averages 17.0 °C – bracing, so a wetsuit helps for longer swims. Expect around 5 hours of sunshine a day. Rain is frequent, with about 13 rainy days and 202 mm in total. All in all, October is not an ideal month for a holiday in Viana do Castelo.
More details for October
- Daylight
- 11 h 10 min07:46 – 18:56
- UV index
- 4 · moderateclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 20 km/haverage daily peakAll months
- Cloud cover
- 57 %on averageAll months
- Hot days
- 0 days30 °C or more
- Time zone
- UTC+1Europe/Lisbon
How the score comes together
- Temperatureweight 35 %0 %
- Seaweight 25 %0 %
- Sunshineweight 20 %40 %
- Few rainy daysweight 20 %34 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Sun, sea & sand”.
What to pack in October
- Wetsuit for longer swims
- Sunscreen
- A jumper for the evenings
- Rain jacket or umbrella
Sea temperature in Viana do Castelo
Monthly sea surface temperature with the range of cooler and warmer years.
8 in 10 years: 15.7 – 18.5 °C
Swimming season: Never above 20 °C
- cold
- fresh
- refreshing
- pleasant
- warm
- very warm
The sea temperature in Viana do Castelo ranges from 13.4 °C in February to 17.2 °C in August. Even at its warmest the sea stays below 20 °C, so swimming is bracing at best.
From November to January the sea is even warmer than the afternoon air. The sea temperature varies from year to year: in August, eight out of ten years were between 16.2 and 18.3 °C.
| Month | Average | Cool year | Warm year | Feels |
|---|---|---|---|---|
| JanuaryJan | 13.9° | 12.9° | 14.7° | cold |
| FebruaryFeb | 13.4° | 12.6° | 14.2° | cold |
| MarchMar | 13.7° | 12.8° | 14.3° | cold |
| AprilApr | 14.6° | 13.6° | 15.8° | cold |
| MayMay | 15.5° | 14.6° | 16.7° | cold |
| JuneJun | 16.7° | 16.0° | 17.6° | cold |
| JulyJul | 17.0° | 16.4° | 18.2° | fresh |
| AugustAug | 17.2° | 16.2° | 18.3° | fresh |
| SeptemberSep | 17.2° | 15.6° | 18.5° | fresh |
| OctoberOct | 17.0° | 15.7° | 18.5° | fresh |
| NovemberNov | 15.9° | 14.6° | 17.3° | cold |
| DecemberDec | 14.6° | 13.6° | 15.6° | cold |
Sunshine hours in Viana do Castelo
Average hours of bright sunshine per day, next to the length of the day. Tap a month to select it.
In October, the sun shines for about 5.4 of 11.2 hours of daylight in Viana do Castelo, 48 % of the day.
Sunshine hours: estimated from radiation data (ERA5, 1996–2025) and calibrated against measured station values; no weather station is close enough here. Daylight is the time from sunrise to sunset on the 15th of the month.
UV index in Viana do Castelo
How strong the sun is at noon, month by month, and how quickly unprotected skin burns.
- Clear-sky UV in October
- 4 · moderateAround midday seek shade; use sunscreen, a hat and sunglasses.
The sun is strongest in June (UV 9).
Minutes until sunburn in October
- Very fair skin
- about 35 min
- Fair skin
- about 45 min
- Light brown skin
- about 65 min
- Olive skin
- about 80 min
Rough guide for unprotected skin at noon under a clear sky; clouds lengthen it, water, sand and snow shorten it. Sunscreen extends the time only partly.
Monthly values: clear-sky noon estimate from the sun's angle, ozone and altitude. UV today: Open-Meteo forecast.
Rain in Viana do Castelo: rainy days and rainfall
A rainy day is a day with at least 1 mm of rain or snow; the amount is what falls in the whole month. Tap a month to select it.
In October, Viana do Castelo has about 13 rainy days with 202 mm of rain in total.
Wind and clouds in Viana do Castelo
How breezy and how cloudy Viana do Castelo is through the year. Tap a month to select it on the whole page.
Wind
Typical daily peak of the wind in km/h: what the afternoon breeze usually reaches, not the gusts.
In October, the wind in Viana do Castelo typically peaks at 20 km/h during the day: Beaufort 4, moderate breeze.
Breezy months for windsurfing and kiting
From Beaufort 4 (20 km/h) the daily breeze is usually enough for windsurfing and often for kiting: Oct – Aug.
Clouds
Average share of the sky covered by cloud, day and night.
In October, cloud covers on average 57 % of the sky over Viana do Castelo: variable cloud, with about 5.4 hours of sunshine a day.
Wind: mean daily maximum of the hourly wind 10 m above ground (ERA5, 1996–2025). Gusts are stronger, and the model grid of about 28 km smooths out local effects such as capes and valley winds. Clouds: mean total cloud cover of all layers over day and night (ERA5, 1996–2025). Thin high cloud counts as cover even when the sun still shines through.
Climate through the year
Long-term monthly averages. Tap a month to see its details.
Nights and sleep in Viana do Castelo
How warm the nights get in each month, from the mean night-time low. Tap a month for details.
- Cool 8–15°
- Pleasant 15–20°
CoolOctober: nights around 14°. A duvet at night and a jumper for the evening.
The coolest nights are in January (8°), the warmest in August (17°). Nights are pleasant for sleeping (15 to 20 °C) from June to September.
Temperatures through the year
Average daytime high, night-time low and sea temperature per month.
| Month | Score | Day | Night | Sea | Sun | Rain days | Rain mm |
|---|---|---|---|---|---|---|---|
| JanuaryJan | 10 | 13° | 8° | 13.9° | 3.8 h | 13 | 178 |
| FebruaryFeb | 18 | 14° | 8° | 13.4° | 5.1 h | 10 | 112 |
| MarchMar | 19 | 15° | 9° | 13.7° | 6.1 h | 12 | 143 |
| AprilApr | 23 | 16° | 11° | 14.6° | 7.3 h | 12 | 130 |
| MayMay | 29 | 18° | 13° | 15.5° | 8.4 h | 10 | 94 |
| JuneJun | 46 | 21° | 15° | 16.7° | 9.4 h | 7 | 45 |
| JulyJul | 60 | 23° | 17° | 17.0° | 10.3 h | 4 | 23 |
| AugustAug | 63 | 23° | 17° | 17.2° | 9.8 h | 4 | 26 |
| SeptemberSep | 47 | 22° | 16° | 17.2° | 7.9 h | 7 | 71 |
| OctoberOct | 15 | 19° | 14° | 17.0° | 5.4 h | 13 | 202 |
| NovemberNov | 9 | 15° | 11° | 15.9° | 4.0 h | 14 | 188 |
| DecemberDec | 8 | 14° | 9° | 14.6° | 3.5 h | 14 | 193 |
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences
41.69° N, 8.83° W · 12 m · Europe/Lisbon
Best time to visit Viana do Castelo
The best time to visit Viana do Castelo is from July to August. The sea stays too cool for a classic beach holiday: even in August it only reaches 17.2 °C. For sightseeing, day trips and hiking, conditions are most comfortable in March and from May to September. Rain is most frequent in April and from October to January; the wettest month is October with 202 mm.
Viana do Castelo through the seasons
How the weather changes over the seasons, with averages for each.
Viana do Castelo in spring
Mar – May
Poor
- 15–18 °C by day
- Sea 15 °C
- 7 h of sun a day
- 34 rainy days in all
Viana do Castelo in summer
Jun – Aug
Fair
- 21–23 °C by day
- Sea 17 °C
- 10 h of sun a day
- 14 rainy days in all
Viana do Castelo in autumn
Sep – Nov
Poor
- 15–22 °C by day
- Sea 17 °C
- 6 h of sun a day
- 34 rainy days in all
Viana do Castelo in winter
Dec – Feb
Poor
- 13–14 °C by day
- Sea 14 °C
- 4 h of sun a day
- 37 rainy days in all
Find your perfect month
Tell us what you like and we rate every month in Viana do Castelo for you.
Your best months: July – August
Based on the climate averages; tap a month to see its details.
Compare two months in Viana do Castelo
Pick two months to see how the weather differs. A tick marks the clearly better value; for temperatures it depends on your plans.
August has the better holiday weather in Viana do Castelo: score 63 against 15. In August, days are 4 °C warmer than in October. The sea is about as warm in both months. August has 9 fewer rainy days. The sun shines 4 hours longer a day in August.
| Month | October | August |
|---|---|---|
| Weather score | 15 | 63better |
| Day high | 19° | 23° |
| Night low | 14° | 17° |
| Sea | 17.0° | 17.2° |
| Sunshine | 5.4 h | 9.8 hbetter |
| Rainy days | 13 | 4better |
| Rainfall | 202 mm | 26 mmbetter |
| Muggy days | 0better | 2 |
Based on the climate averages 1996–2025.
Which month for what?
Beach & swimming
No month
Sea from 21 °C, warm and mostly dry
Sightseeing & hiking
Mar, May – Sep
15–28 °C and not too much rain
Rainy months
Apr, Oct – Jan
12 or more rainy days
Viana do Castelo month by month
The typical weather for every month at a glance.
10January13° · Sea 14° · 4 h
In January, Viana do Castelo is cool: daytime highs average 13 °C, and nights cool down to about 8 °C. The sea averages 13.9 °C – swimming is only for the hardy. The sun is scarce, with only about 4 hours a day. Rain is frequent, with about 13 rainy days and 178 mm in total. All in all, January is not an ideal month for a holiday in Viana do Castelo.
Viana do Castelo in January18February14° · Sea 13° · 5 h
In February, Viana do Castelo is cool: daytime highs average 14 °C, and nights cool down to about 8 °C. The sea averages 13.4 °C – swimming is only for the hardy. Expect around 5 hours of sunshine a day. Rain is frequent, with about 10 rainy days and 112 mm in total. All in all, February is not an ideal month for a holiday in Viana do Castelo.
Viana do Castelo in February19March15° · Sea 14° · 6 h
In March, Viana do Castelo is cool: daytime highs average 15 °C, and nights cool down to about 9 °C. The sea averages 13.7 °C – swimming is only for the hardy. Expect around 6 hours of sunshine a day. Rain is frequent, with about 12 rainy days and 143 mm in total. All in all, March is not an ideal month for a holiday in Viana do Castelo.
Viana do Castelo in March23April16° · Sea 15° · 7 h
In April, Viana do Castelo is mild: daytime highs average 16 °C, and nights cool down to about 11 °C. The sea averages 14.6 °C – swimming is only for the hardy. The sun shines for around 7 hours a day. Rain is frequent, with about 12 rainy days and 130 mm in total. All in all, April is not an ideal month for a holiday in Viana do Castelo.
Viana do Castelo in April29May18° · Sea 16° · 8 h
In May, Viana do Castelo is mild: daytime highs average 18 °C, and nights cool down to about 13 °C. The sea averages 15.5 °C – swimming is only for the hardy. The sun shines for around 8 hours a day. Rain is frequent, with about 10 rainy days and 94 mm in total. All in all, May is not an ideal month for a holiday in Viana do Castelo.
Viana do Castelo in May46June21° · Sea 17° · 9 h
In June, Viana do Castelo is mild: daytime highs average 21 °C, and nights cool down to about 15 °C. The sea averages 16.7 °C – swimming is only for the hardy. With around 9 hours of sunshine a day, there is plenty of sun. Rain falls on about 7 days, adding up to 45 mm. All in all, June is a so-so month for a holiday in Viana do Castelo.
Viana do Castelo in June60July23° · Sea 17° · 10 h
In July, Viana do Castelo is warm: daytime highs average 23 °C, and nights cool down to about 17 °C. The sea averages 17.0 °C – bracing, so a wetsuit helps for longer swims. With around 10 hours of sunshine a day, there is plenty of sun. Rain is rare: about 4 days bring 23 mm in total. All in all, July is a good month for a holiday in Viana do Castelo.
Viana do Castelo in July63August23° · Sea 17° · 10 h
In August, Viana do Castelo is warm: daytime highs average 23 °C, and nights cool down to about 17 °C. The sea averages 17.2 °C – bracing, so a wetsuit helps for longer swims. With around 10 hours of sunshine a day, there is plenty of sun. Rain is rare: about 4 days bring 26 mm in total. All in all, August is a good month for a holiday in Viana do Castelo.
Viana do Castelo in August47September22° · Sea 17° · 8 h
In September, Viana do Castelo is warm: daytime highs average 22 °C, and nights cool down to about 16 °C. The sea averages 17.2 °C – bracing, so a wetsuit helps for longer swims. The sun shines for around 8 hours a day. Rain falls on about 7 days, adding up to 71 mm. All in all, September is a so-so month for a holiday in Viana do Castelo.
Viana do Castelo in September15October19° · Sea 17° · 5 h
In October, Viana do Castelo is mild: daytime highs average 19 °C, and nights cool down to about 14 °C. The sea averages 17.0 °C – bracing, so a wetsuit helps for longer swims. Expect around 5 hours of sunshine a day. Rain is frequent, with about 13 rainy days and 202 mm in total. All in all, October is not an ideal month for a holiday in Viana do Castelo.
Viana do Castelo in October9November15° · Sea 16° · 4 h
In November, Viana do Castelo is cool: daytime highs average 15 °C, and nights cool down to about 11 °C. The sea averages 15.9 °C – swimming is only for the hardy. Expect around 4 hours of sunshine a day. Rain is frequent, with about 14 rainy days and 188 mm in total. All in all, November is not an ideal month for a holiday in Viana do Castelo.
Viana do Castelo in November8December14° · Sea 15° · 4 h
In December, Viana do Castelo is cool: daytime highs average 14 °C, and nights cool down to about 9 °C. The sea averages 14.6 °C – swimming is only for the hardy. The sun is scarce, with only about 4 hours a day. Rain is frequent, with about 14 rainy days and 193 mm in total. All in all, December is not an ideal month for a holiday in Viana do Castelo.
Viana do Castelo in DecemberViana do Castelo compared
Put Viana do Castelo side by side with another destination.
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Viana do Castelo vs. Braga
In October Braga has the better holiday weather (score 24 vs. 15). During the day Braga is 1 °C warmer than Viana do Castelo.
| in October | Viana do Castelo | Braga |
|---|---|---|
| Holiday score | 15 | 24 |
| Daytime high | 19° | 20° |
| Sea | 17° | – |
| Sunshine | 5 h | 5 h |
| Rainy days | 13 | 13 |
| Best time | Jul – Aug | Jun – Sep |
Through the year
Portugal in October: the best places
In October, Viana do Castelo ranks 24 of 24 destinations in this country.
- Sintra20°80
- 2Amadora21°19°80
- 3Lisbon21°19°80
- 4Coimbra22°74
- 5Fátima21°74
- 6Funchal21°23°74
- 7Porto21°17°69
- 8Guimarães20°68
- 24Viana do CasteloThis page19°17°15
Planning a trip to Viana do Castelo
Weather for your travel dates
Pick your arrival and length of stay, and we sum up the weather to expect.
Viana do Castelo in the school holidays
How the weather suits the usual holiday periods. Dates vary by school and region, so each holiday uses the months it usually falls in.
Viana do Castelo has its best school-holiday weather during the summer holidays (score 62) and its weakest during the Christmas holidays (score 9).
- 22
Easter holidays
Mar – Apr
Poor
- 16 °C by day
- Sea 14 °C
- 6.9 h of sun a day
- 12 rainy days a month
Keep in mind: Frequent rain
- 32
May half-term
May – Jun
Poor
- 19 °C by day
- Sea 16 °C
- 8.6 h of sun a day
- 9 rainy days a month
Good for: Sightseeing & walks
- 62
Summer holidays
Jul – Aug
GoodBest holidays
- 23 °C by day
- Sea 17 °C
- 10.0 h of sun a day
- 4 rainy days a month
Good for: Sightseeing & walks
- 15
October half-term
Oct
Poor
- 19 °C by day
- Sea 17 °C
- 5.4 h of sun a day
- 13 rainy days a month
Keep in mind: Frequent rain
- 9
Christmas holidays
Dec – Jan
Poor
- 13 °C by day
- Sea 14 °C
- 3.7 h of sun a day
- 14 rainy days a month
Keep in mind: Frequent rain
Based on the climate averages 1996–2025.
Getting there
Flying from
- Nonstop flight
- about 2 h
- Distance
- 1,260 km
- Time zone
- UTC+1
- Jet lag
- Hardly any (under 3 h)
Estimated from the straight-line distance: 30 minutes for take-off and landing plus 830 km/h cruising speed.
Frequently asked questions about Viana do Castelo
When is the best time to visit Viana do Castelo?
The best time to visit Viana do Castelo is from July to August. That is when the holiday weather score, which combines temperature, sea, sunshine and rain, is highest.
How warm is the sea in Viana do Castelo?
The sea temperature in Viana do Castelo ranges from 13.4 °C in February to 17.2 °C in August. Even at its warmest the sea stays below 20 °C, so swimming is bracing at best.
Can you swim in Viana do Castelo in October?
Only if you don't mind cold water: in October the sea averages just 17.0 °C. Comfortable swimming temperatures are not reached at any time of year.
What is the warmest month in Viana do Castelo?
August is the warmest month, with average highs of 23 °C and nights around 17 °C. January is the coolest month at 13 °C.
When does it rain most in Viana do Castelo?
Rain is most frequent in April and from October to January; the wettest month is October with 202 mm. The driest month is July with 23 mm.
How many hours of sunshine does Viana do Castelo get?
Viana do Castelo gets around 2,470 hours of sunshine a year. The sunniest month is July with 10.3 hours a day; in December there are 3.5 hours a day.
What time zone is Viana do Castelo in?
Viana do Castelo uses the time zone Europe/Lisbon: UTC+0 in January and UTC+1 in July.
How long is the flight from London to Viana do Castelo?
A nonstop flight from London to Viana do Castelo takes about 2 h, for a straight-line distance of about 1,260 km.
Which school holidays are best for Viana do Castelo?
Viana do Castelo has its best school-holiday weather during the summer holidays (score 62) and its weakest during the Christmas holidays (score 9). Holiday ratings (0–100): Easter holidays 22, May half-term 32, Summer holidays 62, October half-term 15, Christmas holidays 9.
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