Surf Forecasts:
Guethary - Les Alcyons/Avalanche surf forecast from 6 Aug 2026:
- Most powerful swell: Thursday 13 Aug, 5PM (local time) - 2ft (0.6m), 12s period, WNW swell with 106 kJ wave energy.
Best Forecast Surf Conditions for Guethary - Les Alcyons/Avalanche this week:
The most powerful waves expected at Guethary - Les Alcyons/Avalanche in the next 16 days are 0.6m 12s and forecast to arrive on Thursday (Aug 13) at 5PM. Winds are predicted to be onshore at the time the swell arrives.
| Wave Type | Time (CEST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 5PM (Thu 13th Aug) | 2ft (0.6m) 12s |
Table - best surf conditions forecast for Guethary - Les Alcyons/Avalanche over the next 16 days.
The Lowdown
Alright, Rusty here. Let’s have a look at what’s on offer for the next couple of weeks.
Honestly, it’s a bleak stretch ahead. The whole 16-day window is a write-off for any decent surf. We’re looking at a solid two weeks with nothing to get excited about. The first day with any recommendation is the 6th of August, but even then, it’s a no-go. The pattern is consistent: small, weak, and messy.
The only spot in the frame is Guethary - Les Alcyons/Avalanche (France), a reef break that’s only for experts. The water’s sitting at 77°, which is much warmer than normal for this time of year—over three degrees above average, which is very unusual.
From the 6th through to the 21st of August, every single session is marked as poor surf conditions. The swell is tiny, mostly hanging around 1 ft to 3 ft, with short periods of 5 to 10 seconds. The combined energy is weak, reading between 14 and 168, which tells you there’s just no power. The wind is a constant issue—mostly onshore or cross-on from the northwest, so it’s choppy and unruly. There are a few glassy mornings, like the 7th, 8th, 11th, 14th, and 19th, but with barely a ripple of swell, it’s flat and clean, not surfable. The best of the bunch might be the 21st of August afternoon, with a 4 ft swell from the west-northwest, but it’s a short-period 6 seconds and onshore wind at 12 mph, so it’s just a messy, blown-out lump.
There’s nothing here for anyone. No standouts, no hidden gems. For a break that’s consistent and exposed, it’s a rare blank run. It tends not to stay this poor for long, but right now, the forecasts are clear: leave the boards at home.
Rusty.
Short Range ForecastLight rain (total 5mm), mostly falling on Sat night. Warm (max 25°C on Sat afternoon, min 18°C on Thu night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 9mm), mostly falling on Sun night. Warm (max 25°C on Tue afternoon, min 19°C on Mon night). Wind will be generally light. | |||||||||||||||||||
Thu 6 | Friday 7 | Saturday 8 | Sunday 9 | Monday 10 | Tuesday 11 | Wednesday 12 | ||||||||||||||
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 | NNW 6 | NNW 6 | NNW 6 | NNW 5 | NW 12 | NW 10 | NW 10 | NW 10 | NW 9 | NW 9 | NW 9 | NW 8 | NW 8 | NW 8 | NW 8 | WNW 10 | WNW 9 |
Wave Graph  | ||||||||||||||||||||
 kJ | 109 | 82 | 46 | 33 | 33 | 12 | 11 | 22 | 89 | 96 | 88 | 67 | 81 | 64 | 69 | 69 | 41 | 34 | 33 | 26 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | glassy | glassy | on | cross | glassy | on | cross | cross-on | on | glassy | glassy | on | glassy | glassy | on | cross-on | cross-on | on | cross |
High Tide | 10:56PM3.03m | 11:36AM2.95m | 00:20AM2.92m | 1:03PM2.97m | 1:51AM2.98m | 2:25PM3.17m | 3:06AM3.18m | 3:31PM3.46m | 4:06AM3.43m | 4:25PM3.77m | 4:56AM3.64m | 5:13PM4.01m | ||||||||
Low Tide | 4:37PM0.91m | 5:14AM0.97m | 5:53PM1.00m | 6:34AM1.05m | 7:20PM0.94m | 7:56AM0.96m | 8:38PM0.72m | 9:04AM0.74m | 9:41PM0.43m | 10:01AM0.47m | 10:34PM0.15m | 10:50AM0.23m | 11:22PM-0.05m | |||||||
 |  | | | | | |  |  | | | | | | | | | | | | |
 | — | — | 7:01 | — | — | 7:03 | — | — | 7:03 | — | — | 7:05 | — | — | 7:05 | — | — | 7:07 | — | — |
 | — | 9:22 | — | — | 9:21 | — | — | 9:20 | — | — | 9:19 | — | — | 9:16 | — | — | 9:15 | — | — | 9:14 |
mm | — | — | — | — | — | — | — | 5 | — | — | 9 | — | — | — | — | — | — | — | — | — |
Temp °C | 22 | 21 | 20 | 23 | 22 | 23 | 25 | 22 | 22 | 23 | 21 | 22 | 23 | 22 | 22 | 25 | 23 | 22 | 24 | 23 |
Feels °C | 21 | 21 | 21 | 22 | 23 | 24 | 25 | 23 | 24 | 24 | 22 | 25 | 25 | 23 | 25 | 26 | 25 | 23 | 25 | 24 |
Swell 1 Height (m) Direction Period (s) | NW 8 | NW 8 | NW 7 | NNW 6 | NNW 6 | NNW 6 | NNW 5 | NW 4 | NW 10 | NW 10 | NW 10 | NW 9 | NW 9 | NW 9 | NW 8 | NW 8 | NW 8 | NW 8 | NW 8 | WNW 9 |
| kJ | 109 | 82 | 46 | 33 | 33 | 12 | 11 | 15 | 89 | 96 | 88 | 67 | 81 | 64 | 69 | 69 | 41 | 34 | 28 | 26 |
Swell 2 Height (m) Direction Period (s) | WNW 10 | WNW 10 | WNW 10 | WNW 10 | WNW 9 | W 9 | W 9 | NW 12 | NW 4 | NW 4 | W 8 | NW 4 | WNW 4 | NW 4 | NW 11 | — | NNW 4 | NNW 4 | WNW 10 | NW 8 |
| kJ | 10 | 10 | 9 | 9 | 8 | 2 | 2 | 22 | 10 | 4 | 1 | 6 | 2 | 3 | 4 | — | 7 | 3 | 33 | 20 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | N 10 | NW 6 | W 9 | W 8 | — | W 8 | — | — | — | — | WNW 10 | WNW 11 | — | — |
| kJ | — | — | — | — | — | — | 2 | 2 | 2 | 1 | — | 1 | — | — | — | — | 9 | 12 | — | — |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | NW 4 | — | — | — | — | — | — | WSW 3 | — | — |
| kJ | — | — | — | — | — | — | — | — | — | — | 4 | — | — | — | — | — | — | 1 | — | — |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 87 | 1 | 1 | 619 | 31 | 558 | 347 | 31 | 189 | 196 | 1 | 1 | 87 | 1 | 1 | 197 | 17 | 31 | 356 | 31 |
Best forecast wave conditions in La Cote Basque | ||||||||||||||||||||
Best forecast wave conditions in France | ||||||||||||||||||||
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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.
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