Surf Forecasts:
Viana do Castelo surf forecast from 23 Aug 2026:
- Best quality surf: Friday 28 Aug, 1AM (local time) - 7ft (2.1m), 9s period, WNW swell with cross-shore winds.
- Most powerful swell: Friday 28 Aug, 10AM (local time) - 8ft (2.5m), 11s period, WNW swell with 1,597 kJ wave energy.
- Next surfable swell (1★+): Sunday 23 Aug, 7AM (local time) - 5ft (1.6m), 11s period with W swell.
Best Forecast Surf Conditions for Viana do Castelo this week:
The surf forecast for Viana do Castelo over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Sunday (Aug 23) at 7AM. The primary swell is predicted to be 1.6m and 11s period with a secondary swell of 0.4m and 8s. The wind is predicted to be offshore as the swell arrives.
The most powerful waves expected at Viana do Castelo in the next 16 days are 2.5m 11s and forecast to arrive on Friday (Aug 28) at 10AM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.2m 3s period and expected on Saturday (Aug 29) at 7PM.
| Wave Type | Time (WEST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 7AM (Sun 23rd Aug) | 5ft (1.6m) 11s |
| Best Surf | 1AM (Fri 28th Aug) | 7ft (2.1m) 9s |
| Most Powerful | 10AM (Fri 28th Aug) | 8ft (2.5m) 11s |
Table - best surf conditions forecast for Viana do Castelo over the next 16 days.
The Lowdown
Alright, Rusty here. Let’s talk about what’s shaping up for the waves at Viana do Castelo. This is a river mouth setup that needs the right conditions to really fire, and we’ve got a mixed bag over the next couple of weeks.
We start off on Sunday, August 23rd morning with a glimmer of hope. There’s a clean 5ft swell from the west with a 10-second period and a light north breeze blowing cross-offshore. The water’s about average for the time of year, and with combined swell energy at 529, it’s moderate. It’s a decent little window, but don’t get too excited—crowds are often here, and the river mouth can be fickle. This is the standout of the early period, but it’s fleeting.
After that, things go flat and ugly. From Sunday afternoon all the way through Thursday, August 27th, the wind’s onshore or cross-shore from the south and southwest, the swell drops, and the period gets short. It’s a poor run of surf, with energy values ranging from 90 to 538. Thursday afternoon is marginal at best with a 6ft west swell but onshore wind.
Then we get a big, powerful pulse. On Friday, August 28th, a strong groundswell from the west-northwest hits with an 8ft swell and an 11-second period. The energy jumps to a massive 1597. But here’s the catch: this is a river break, and 8ft is too big for it. The wind is light, but the wave height will be closing out and messy. Only for experts, and even then, it’s a risk. Friday afternoon is the same story—8ft from the northwest.
Saturday, August 29th morning is another small window of quality. A clean 5ft northwest swell with glassy conditions and zero wind. The energy’s moderate at 430. This could be a nice session if you time it right, but the afternoon gets a cross-shore breeze and drops off.
From there, we hit a long dry spell. Sunday, August 30th through Wednesday, September 2nd is mostly small, weak, and onshore or glassy but tiny. Energy values are below 200. The waves are surfable but nothing to write home about. Thursday and Friday, September 3rd and 4th are mostly tiny and weak, with a bit of cross-offshore wind but barely a ripple.
The tail end of the forecast shows a small uptick. On Monday, September 7th morning, there’s a 5ft west-northwest swell with a light cross-offshore breeze from the north-northwest, giving clean conditions. The period is a weak 9 seconds, but it’s the best we’ve seen in a week. It’s still marginal for the break.
So, to wrap it up: Sunday morning August 23rd and Saturday morning August 29th are your best bets for a clean, fun session at Viana do Castelo. The big swell on August 28th is too much for this spot. After that, it’s a long wait until September 7th for another chance. Keep an eye on the forecasts, but for now, it’s mostly a waiting game.
Rusty.
Short Range ForecastHeavy rain (total 28mm), heaviest during Mon morning. Warm (max 21°C on Sun afternoon, min 17°C on Sat night). Winds increasing (calm on Sat night, fresh winds from the SSE by Mon morning). | Days 4-6 Weather SummaryHeavy rain (total 37mm), heaviest during Thu afternoon. Warm (max 20°C on Wed morning, min 16°C on Wed night). Wind will be generally light. | ||||||||||||||||||||
Sunday 23 | Monday 24 | Tuesday 25 | Wednesday 26 | Thursday 27 | Friday 28 | Saturday 29 | |||||||||||||||
AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | |
Swell Height Map | |||||||||||||||||||||
Wave Height (m) Direction Period (s) | W 10 | W 10 | SW 9 | SW 8 | SSW 8 | SW 7 | SW 6 | W 6 | W 6 | WSW 6 | WSW 7 | W 8 | W 8 | W 8 | WNW 9 | WNW 11 | NW 10 | NW 10 | NW 9 | NW 9 | NW 8 |
Wave Graph | |||||||||||||||||||||
510 | 306 | 481 | 445 | 527 | 205 | 94 | 52 | 49 | 97 | 212 | 477 | 401 | 435 | 632 | 1597 | 1240 | 800 | 430 | 311 | 156 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-on | cross-off | cross | cross-on | cross-on | cross-on | on | cross | cross-on | on | on | cross-on | on | cross | cross | on | off | glassy | cross | glassy |
High Tide | 12:43PM2.59m | 1:23AM2.50m | 1:39PM2.77m | 2:09AM2.67m | 2:21PM2.96m | 2:45AM2.85m | 2:56PM3.15m | 3:17AM3.02m | 3:28PM3.31m | 3:48AM3.18m | 4:00PM3.44m | 4:19AM3.30m | 4:32PM3.52m | ||||||||
Low Tide | 6:18AM1.55m | 7:10PM1.41m | 7:18AM1.41m | 7:57PM1.22m | 8:02AM1.23m | 8:34PM1.03m | 8:39AM1.04m | 9:07PM0.85m | 9:12AM0.85m | 9:38PM0.69m | 9:45AM0.70m | 10:09PM0.57m | 10:18AM0.59m | 10:41PM0.50m | |||||||
6:50 | — | — | 6:52 | — | — | 6:52 | — | — | 6:54 | — | — | 6:54 | — | — | 6:56 | — | — | 6:56 | — | — | |
— | 8:23 | — | — | 8:22 | — | — | 8:21 | — | — | 8:19 | — | — | 8:16 | — | — | 8:15 | — | — | 8:14 | — | |
mm | 3 | 1 | 4 | 6 | 6 | 6 | 2 | — | 4 | 4 | 2 | 14 | 5 | 8 | — | — | — | — | — | — | — |
Temp °C | 19 | 21 | 19 | 19 | 20 | 19 | 21 | 21 | 18 | 20 | 20 | 17 | 17 | 17 | 16 | 19 | 20 | 18 | 21 | 21 | 19 |
Feels °C | 18 | 18 | 17 | 16 | 18 | 20 | 21 | 20 | 18 | 18 | 17 | 15 | 16 | 16 | 16 | 17 | 19 | 18 | 19 | 19 | 19 |
Swell 1 Height (m) Direction Period (s) | W 10 | W 10 | SW 9 | SW 8 | N 7 | SW 7 | SW 6 | W 6 | W 6 | WSW 6 | WNW 8 | W 8 | W 8 | W 8 | WNW 9 | WNW 11 | NW 10 | NW 10 | NW 9 | NW 9 | NW 8 |
510 | 306 | 481 | 445 | 4 | 205 | 94 | 52 | 49 | 97 | 39 | 477 | 401 | 435 | 632 | 1597 | 1240 | 800 | 430 | 311 | 156 | |
Swell 2 Height (m) Direction Period (s) | NNW 8 | SW 6 | NNW 8 | NNW 7 | SW 13 | N 6 | N 6 | SSW 6 | NW 10 | NW 9 | SW 12 | — | SW 11 | S 11 | S 11 | — | — | — | — | — | — |
11 | 58 | 11 | 5 | 7 | 1 | 1 | 33 | 15 | 21 | 5 | — | 5 | 2 | 2 | — | — | — | — | — | — | |
Swell 3 Height (m) Direction Period (s) | SW 14 | NNW 8 | SW 13 | SW 13 | — | SW 13 | SW 12 | NW 11 | W 9 | SW 12 | N 6 | — | — | — | S 11 | — | — | — | — | — | — |
8 | 11 | 7 | 7 | — | 6 | 6 | 5 | 2 | 6 | 1 | — | — | — | 2 | — | — | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | — | — | — | — | SSW 8 | — | — | — | SSW 6 | S 5 | WSW 7 | — | — | — | — | — | — | — | — | — | — |
— | — | — | — | 527 | — | — | — | 18 | 40 | 212 | — | — | — | — | — | — | — | — | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 0 | 18 | 2 | 106 | 106 | 66 | 81 | 114 | 2 | 104 | 179 | 80 | 104 | 114 | 2 | 10 | 104 | 2 | 0 | 104 | 0 |
Best forecast wave conditions in Douro and Minho | |||||||||||||||||||||
Best forecast wave conditions in Portugal | |||||||||||||||||||||
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Information about the Viana do Castelo Surf forecast
The above surf forecast table for Viana do Castelo provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Viana do Castelo can be found by selecting the local surf guide option on the grey menu. Our Viana do Castelo surf forecast is unique since it includes wave energy (power) that defines the real feel of the surf rather than just the height or the period. If you surf the same spot (Viana do Castelo) regularly then make a mental note of the wave energy from the surf forecast table each time you go. Very soon you may start to choose your surf days based on the wave energy alone combined with our forecast of favourable offshore wind conditions. Our star ratings will help here and of course you will also find the usual wave height and period predictions on our surf forecasts as well as a full break down of the swell components under our advanced users option (to reveal that, click the little Einstein character under the tide times).
Further information to help with frequently asked questions about our surf forecast for Viana do Castelo may be found under the help tab on the top menu and also by moving your mouse over the question marks on the surf forecast table itself. Please always bear in mind that the forecast is for near-shore open water and local factors at each surf break influence the actual breaking wave height, such as the beach / reef profile, water depths offshore and shelter.
Viana do Castelo is 3 km (2 miles) from Viana do Castelo. If you plan a holiday in Douro and Minho, look for hotels and other accommodation in Viana do Castelo. Viana do Castelo has rooms for a wide range of budgets as well as car hire and transport links.











