Surf Forecasts:
Guethary - Les Alcyons/Avalanche surf forecast from 16 Aug 2026:
- Best quality surf: Friday 21 Aug, 8AM (local time) - 4.5ft (1.4m), 11s period, NW swell with glassy winds.
- Most powerful swell: Friday 21 Aug, 5AM (local time) - 4.5ft (1.4m), 11s period, NW swell with 415 kJ wave energy.
- Next surfable swell (1★+): Thursday 20 Aug, 5AM (local time) - 2ft (0.6m), 12s period with NW swell.
Best Forecast Surf Conditions for Guethary - Les Alcyons/Avalanche this week:
The surf forecast for Guethary - Les Alcyons/Avalanche over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Thursday (Aug 20) at 5AM. The primary swell is predicted to be 0.6m and 12s period with a secondary swell of 0.4m and 5s. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Guethary - Les Alcyons/Avalanche in the next 16 days are 1.4m 11s and forecast to arrive on Friday (Aug 21) at 5AM. Winds are predicted to be cross-shore at the time the swell arrives.
| Wave Type | Time (CEST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 5AM (Thu 20th Aug) | 2ft (0.6m) 12s |
| Best Surf | 8AM (Fri 21st Aug) | 4.5ft (1.4m) 11s |
| Most Powerful | 5AM (Fri 21st Aug) | 4.5ft (1.4m) 11s |
Table - best surf conditions forecast for Guethary - Les Alcyons/Avalanche over the next 16 days.
The Lowdown
Alright, let's talk about what we've got for the next couple of weeks. To be blunt, it's a bit of a slow grind, especially at the start. Guethary - Les Alcyons/Avalanche (Pays Basque) is going to be mostly flat and messy, so you'll need to pick your moments.
For the first several days, there's barely a ripple. We're talking ankle-biters under 3ft, with that weak, onshore chop making it a total scratch-fest. The energy readings are rock bottom, like 14 and 28, which tells you everything. You'd be better off fixing a ding or rigging a kite. We don't see any real hope until Friday the 21st.
That Friday morning is the one to circle. The swell comes up to about 4ft, with a 10-second period from the NW. The wind is a light offshore from the ENE, making for some clean, workable conditions. The energy reading jumps to a moderate 364, finally giving you something to push against. This is a reef break, so it's for experts only, and it's consistent, so expect some crew out. But that's your best bet, and it won't last – the wind goes onshore in the afternoon and junk it up.
The weekend after that is nothing special. A small, clean-ish wave on Saturday morning, but it's not worth much. The following week looks like a total write-off until Monday the 24th. The swell energy goes through the roof to a massive 1680, with the swell hitting well over 10ft. But the wind is blowing straight onshore and it's going to be a total mess. That’s not surfable for a paddleboard, it's just for the guys towing in or kites. It's all power and no shape.
The water on the 16th was a balmy 77 degrees, which is almost 6 degrees warmer than it should be. That’s a crazy anomaly, so you won't need a bootie or a spring suit.
So, the bottom line is this: set your alarm for Friday morning, the 21st. That's the standout. The rest of the window is either too small, too messy, or too wild to be any fun for a surfer. It'll be a test of patience, but that's the way it goes sometimes.
Keep it salty.
Rusty
Short Range ForecastMostly dry. Warm (max 23°C on Sun afternoon, min 18°C on Tue night). Wind will be generally light. | Days 4-6 Weather SummaryLight rain (total 2mm), mostly falling on Wed night. Warm (max 23°C on Wed afternoon, min 17°C on Fri night). Wind will be generally light. | ||||||||||||||||||||
Sunday 16 | Monday 17 | Tuesday 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | |||||||||||||||
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) | NW 8 | NW 8 | NW 7 | NW 7 | NW 7 | NW 6 | NW 7 | NW 8 | NNW 6 | NNW 5 | WNW 8 | NW 13 | NW 11 | NW 10 | NW 10 | NW 10 | NW 10 | NW 9 | NW 9 | NW 9 | NW 8 |
Wave Graph  | |||||||||||||||||||||
 kJ | 78 | 78 | 60 | 64 | 54 | 30 | 17 | 53 | 22 | 8 | 6 | 25 | 140 | 170 | 328 | 348 | 315 | 196 | 132 | 93 | 69 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | glassy | on | cross | cross-on | on | glassy | on | on | cross-off | glassy | on | glassy | cross-on | on | cross-on | cross-off | on | cross-off | cross-off | cross-on | cross-off |
High Tide | 7:56PM3.82m | 8:17AM3.50m | 8:34PM3.53m | 8:54AM3.28m | 9:13PM3.21m | 9:33AM3.04m | 9:57PM2.89m | 10:21AM2.81m | 10:56PM2.63m | 11:31AM2.63m | 00:26AM2.48m | 1:09PM2.59m | 2:03AM2.54m | ||||||||
Low Tide | 1:36PM0.16m | 2:03AM0.24m | 2:16PM0.38m | 2:41AM0.52m | 2:57PM0.65m | 3:21AM0.82m | 3:43PM0.94m | 4:07AM1.12m | 4:39PM1.21m | 5:08AM1.36m | 5:56PM1.38m | 6:31AM1.47m | 7:27PM1.38m | ||||||||
 | |  | |  |  | | | | | |  | | | |  | | |  | |  | |
 | 7:11 | — | — | 7:11 | — | — | 7:13 | — | — | 7:15 | — | — | 7:16 | — | — | 7:16 | — | — | 7:18 | — | — |
 | — | — | 9:08 | — | — | 9:07 | — | — | 9:06 | — | — | 9:04 | — | — | 9:01 | — | — | 9:00 | — | 8:59 | — |
mm | — | — | — | — | — | — | — | — | — | — | — | 1 | — | — | — | — | — | 1 | 2 | — | 3 |
Temp °C | 22 | 23 | 22 | 21 | 23 | 22 | 22 | 23 | 22 | 20 | 23 | 21 | 22 | 23 | 21 | 18 | 21 | 21 | 17 | 20 | 19 |
Feels °C | 25 | 24 | 23 | 22 | 25 | 24 | 24 | 23 | 23 | 22 | 24 | 23 | 24 | 23 | 21 | 19 | 20 | 21 | 17 | 18 | 19 |
Swell 1 Height (m) Direction Period (s) | NW 8 | NW 8 | NW 7 | NW 7 | NW 7 | NW 6 | NNW 5 | NW 8 | NNW 6 | NNW 5 | WNW 8 | NNW 5 | NW 11 | NW 10 | NW 10 | NW 10 | NW 10 | NW 9 | NW 9 | NW 9 | NW 8 |
| kJ | 78 | 78 | 60 | 64 | 54 | 30 | 11 | 53 | 22 | 8 | 6 | 5 | 140 | 170 | 328 | 348 | 315 | 196 | 132 | 93 | 69 |
Swell 2 Height (m) Direction Period (s) | — | — | — | — | — | NW 7 | NW 7 | N 7 | WNW 8 | WNW 8 | N 7 | NW 13 | NNW 5 | — | WNW 8 | WNW 9 | WNW 8 | WNW 9 | WNW 9 | WNW 9 | WNW 10 |
| kJ | — | — | — | — | — | 14 | 17 | 4 | 7 | 6 | 1 | 25 | 9 | — | 14 | 16 | 14 | 15 | 7 | 7 | 19 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | NW 11 | — | — | — | — | — | NW 10 | — | — | — | — | — | — | W 11 | WNW 11 | — |
| kJ | — | — | — | — | — | 5 | — | — | — | — | — | 16 | — | — | — | — | — | — | 2 | 12 | — |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | NNW 4 | — | — | NNW 6 | — | — | — | — | — | — | — |
| kJ | — | — | — | — | — | — | — | — | — | — | 4 | — | — | 12 | — | — | — | — | — | — | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 1 | 87 | 17 | 47 | 197 | 1 | 47 | 197 | 530 | 526 | 485 | 1 | 12 | 87 | 6 | 0 | 87 | 0 | 0 | 87 | 1 |
Best forecast wave conditions in La Cote Basque | |||||||||||||||||||||
Best forecast wave conditions in France | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
FREE! Surf-Forecast.com widget for your website
The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Guethary - Les Alcyons/Avalanche surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.
Information about the Guethary - Les Alcyons/Avalanche Surf forecast
The above surf forecast table for Guethary - Les Alcyons/Avalanche provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Guethary - Les Alcyons/Avalanche can be found by selecting the local surf guide option on the grey menu. Our Guethary - Les Alcyons/Avalanche 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 (Guethary - Les Alcyons/Avalanche) 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 Guethary - Les Alcyons/Avalanche 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.
Guethary - Les Alcyons/Avalanche is 9 km (6 miles) from Biarritz. If you plan a holiday in La Cote Basque, look for hotels and other accommodation in Biarritz. Biarritz has rooms for a wide range of budgets as well as car hire and transport links.
Nearest