Surf Forecasts:
Viana do Castelo surf forecast from 18 Aug 2026:
- Best quality surf: Friday 21 Aug, 10PM (local time) - 7ft (2.1m), 10s period, NNW swell with cross-offshore winds.
- Most powerful swell: Friday 21 Aug, 10PM (local time) - 7ft (2.1m), 10s period, NNW swell with 855 kJ wave energy.
- Next surfable swell (1★+): Wednesday 19 Aug, 4AM (local time) - 2.5ft (0.7m), 7s period with NNW 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 Wednesday (Aug 19) at 4AM. The primary swell is predicted to be 0.7m and 7s period with a secondary swell of 0.3m and 8s. Another secondary swell of 0.3m and 3s is also forecast. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Viana do Castelo in the next 16 days are 2.1m 10s and forecast to arrive on Friday (Aug 21) at 10PM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.3m 6s period and expected on Saturday (Aug 22) at 1AM.
| Wave Type | Time (WEST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 4AM (Wed 19th Aug) | 2.5ft (0.7m) 7s |
| Best Surf | 10PM (Fri 21st Aug) | 7ft (2.1m) 10s |
| Most Powerful | 10PM (Fri 21st Aug) | 7ft (2.1m) 10s |
Table - best surf conditions forecast for Viana do Castelo over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s get into it.
First thing’s first: we’ve got a long gap of nothing much to speak of. The first real surf doesn’t pop up until Thursday morning, the 20th of August. Before that, Tuesday and Wednesday are flat to tiny with poor wind, so don’t even bother paddling out.
The standout window is Thursday morning, the 20th. We’re looking at a clean 4 ft swell from the NW, with a cross-off wind from the NNW at 6 mph. The combined energy reads moderate at 290, and while the period is a short 8 seconds, the conditions should be clean and surfable. This is the best bet in the whole run.
Friday morning, the 21st, brings a bigger 5 ft swell from the NNW, period up to 10 seconds, and the combined energy jumps to 534 (moderate to strong). The wind is cross-off from the north at 12 mph, keeping it clean. That’s a solid option, but it’s a bit more powerful and might be too much for beginners.
Saturday morning, the 22nd, drops back to 5 ft from the NNW, with a moderate 9-second period. The energy is still moderate at 365, and the wind is cross-off. It’s a doable session, but not as good as Thursday or Friday.
Sunday the 23rd and Monday the 24th are smaller and a bit wind-affected, so we’ll see a drop in quality.
Then we hit a big gap. From Monday afternoon through most of the following week, the surf is small, wind is messy, and there’s nothing worth chasing. That’s a solid 5 to 6 days of poor conditions.
But hold on – the end of the run looks promising. Thursday morning, the 27th of August, we see a 7 ft swell from the NW, period of 9 seconds, and a massive combined energy of 698 (strong). The wind is light and cross-off from the WNW at 6 mph. That’s a big, clean swell, but at 7 ft, it’s getting into expert territory. Not for the faint of heart.
The real standout in this second week is Friday morning, the 28th of August. We’ve got a 6 ft swell from the WNW, period of 10 seconds, and the energy is strong at 688. The wind is a light cross-off from the north at only 3 mph. Clean lines, solid size, and decent period. This is the one to circle on the calendar. It’s a long-range promise, so don’t hold your breath, but it looks good.
Saturday morning, the 29th, offers a smaller but glassy 5 ft from the WNW with a 9-second period and energy at 304. The wind is glassy – absolute perfection for a clean session. Ideal for all levels.
After that, the surf drops off again into the start of September, with only small, ordinary waves and a bit of cross-off wind.
For the best on offer: Thursday the 20th morning is the cleanest early call. Friday the 28th morning is the biggest, most powerful, and cleanest swell in the whole outlook. Get excited for that one.
The water temperature is 65°F, which is about average for this time of year, so no need to dig out the thickest wetsuit.
Signing off, Rusty.
Short Range ForecastMostly dry. Warm (max 29°C on Tue morning, min 15°C on Thu night). Winds increasing (calm on Tue night, fresh winds from the NNW by Thu afternoon). | Days 4-6 Weather SummaryMostly dry. Warm (max 22°C on Sun morning, min 13°C on Sat night). Mainly strong winds. | ||||||||||||||||||||
Tuesday 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | |||||||||||||||
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) | NNW 8 | NNW 8 | NNW 7 | NW 5 | WNW 10 | WNW 9 | NW 8 | NW 7 | NW 11 | NNW 10 | NW 10 | NNW 10 | NNW 9 | NNW 8 | NNW 7 | NNW 7 | NNW 7 | NNW 7 | NNW 7 | NW 6 | NW 4 |
Wave Graph | |||||||||||||||||||||
88 | 72 | 64 | 13 | 52 | 62 | 216 | 248 | 791 | 448 | 569 | 196 | 307 | 365 | 293 | 208 | 237 | 248 | 56 | 31 | 15 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | on | cross | cross-on | on | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross | glassy |
High Tide | 7:33PM2.93m | 8:00AM2.80m | 8:16PM2.69m | 8:49AM2.63m | 9:13PM2.48m | 9:55AM2.50m | 10:36PM2.35m | 11:23AM2.48m | 00:13AM2.37m | 12:43PM2.59m | 1:23AM2.50m | 1:39PM2.77m | 2:09AM2.67m | ||||||||
Low Tide | 1:18PM1.08m | 1:40AM1.10m | 2:01PM1.29m | 2:23AM1.32m | 2:57PM1.47m | 3:22AM1.50m | 4:20PM1.58m | 4:49AM1.60m | 6:00PM1.55m | 6:18AM1.55m | 7:10PM1.41m | 7:18AM1.41m | 7:57PM1.22m | ||||||||
6:46 | — | — | 6:47 | — | — | 6:48 | — | — | 6:48 | — | — | 6:50 | — | — | 6:50 | — | — | 6:52 | — | — | |
— | 8:30 | — | — | 8:30 | — | — | 8:28 | — | — | 8:27 | — | — | 8:24 | — | — | 8:23 | — | — | 8:22 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 29 | 25 | 21 | 23 | 23 | 19 | 21 | 21 | 18 | 21 | 20 | 18 | 21 | 21 | 18 | 22 | 22 | 19 | 20 | 20 | 17 |
Feels °C | 29 | 25 | 21 | 24 | 24 | 20 | 19 | 17 | 14 | 16 | 14 | 14 | 15 | 14 | 13 | 17 | 16 | 14 | 16 | 16 | 16 |
Swell 1 Height (m) Direction Period (s) | NNW 8 | NNW 8 | NNW 7 | NW 5 | WNW 10 | WNW 9 | NW 11 | W 8 | W 9 | WNW 9 | W 8 | NNW 10 | W 9 | WNW 9 | W 8 | W 8 | W 8 | W 9 | NNW 7 | W 8 | NW 4 |
88 | 72 | 64 | 13 | 52 | 62 | 56 | 51 | 25 | 59 | 36 | 196 | 39 | 25 | 23 | 12 | 12 | 13 | 56 | 12 | 15 | |
Swell 2 Height (m) Direction Period (s) | WNW 8 | W 8 | WNW 8 | WNW 8 | NW 5 | NW 4 | SW 13 | NW 10 | SSW 16 | SSW 15 | SSW 15 | W 10 | SSW 14 | SSW 14 | SW 14 | SW 14 | SW 14 | SW 13 | W 8 | SW 13 | NNW 6 |
12 | 12 | 12 | 12 | 6 | 3 | 7 | 50 | 24 | 21 | 21 | 46 | 19 | 20 | 8 | 8 | 7 | 7 | 11 | 7 | 4 | |
Swell 3 Height (m) Direction Period (s) | SW 17 | SW 16 | SSW 16 | WNW 11 | SSW 4 | NW 12 | SW 16 | SW 13 | SW 16 | SW 12 | W 11 | SSW 15 | — | — | — | — | — | — | SW 13 | NW 9 | W 8 |
11 | 10 | 24 | 11 | 3 | 22 | 11 | 7 | 10 | 6 | 10 | 21 | — | — | — | — | — | — | 7 | 3 | 5 | |
Wind waves Height (m) Direction Period (s) | — | — | S 3 | S 4 | — | — | NW 8 | NW 7 | NW 11 | NNW 10 | NW 10 | NNW 6 | NNW 9 | NNW 8 | NNW 7 | NNW 7 | NNW 7 | NNW 7 | — | NW 6 | — |
— | — | 1 | 2 | — | — | 216 | 248 | 791 | 448 | 569 | 127 | 307 | 365 | 293 | 208 | 237 | 248 | — | 31 | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 0 | 104 | 10 | 146 | 104 | 0 | 0 | 120 | 19 | 100 | 329 | 100 | 258 | 329 | 151 | 38 | 438 | 130 | 256 | 781 | 71 |
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.











