
Surf Forecasts:
Guethary - Les Alcyons/Avalanche surf forecast from 1 Aug 2026:
- Most powerful swell: Thursday 6 Aug, 2PM (local time) - 2.5ft (0.7m), 8s period, NW swell with 69 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 0.7m 8s and forecast to arrive on Thursday (Aug 06) at 2PM. 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 | 2PM (Thu 6th Aug) | 2.5ft (0.7m) 8s |
Table - best surf conditions forecast for Guethary - Les Alcyons/Avalanche over the next 16 days.
The Lowdown
Alright, Rusty here, looking at Guethary - Les Alcyons/Avalanche. This is a reef break, expert only, and it breaks consistently. It’s wide open to a west swell.
Man, what a rough start. The water is sitting at 77° right now, which is a massive 6° warmer than normal for this time of year – that’s a serious anomaly.
We’ve got a big dead zone. From August 1st all the way through the 8th, there’s nothing worth paddling out for. The swell is tiny, the conditions are poor, or both. The combined swell energy is in the teens, twenties, and thirties. Some mornings look glassy, but with swell heights of 1ft to 2ft and a short period, it’s flat. Forget it.
The only real chance pops up on Sunday, August 9th. The morning is the best of the lot. We’re looking at a 4ft swell from the WNW, with an 8-second period, and a glassy, offshore wind from the WNW. The combined energy hits 232 (moderate), and the report says “expect good surf conditions.” That’s your window. The afternoon gets blown out by a NNW wind, so be there early.
Monday the 10th is a runner-up. The morning is glassy with a 3ft NW swell, but the energy is lower (119), and the conditions are just “surfable but very ordinary.” It’s okay, but not the day.
After that, it’s back to the weeds. The 12th of August has a glassy morning with 2ft from the WNW and a period of 10 seconds, and energy of 125, but it’s marginal longboard stuff at best.
The second week is a total fade. From the 13th to the 16th, it’s small, short-period slop with onshore winds. The afternoon of the 16th bumps up to 4ft from the NW, but the period is only 7 seconds and the wind is on it, so it’s a mess.
The only standout is the morning of the 9th of August. That’s your one chance. Everything else is a long wait.
- Rusty
Short Range ForecastLight rain (total 7mm), mostly falling on Mon night. Warm (max 23°C on Sun afternoon, min 18°C on Sat morning). Wind will be generally light. | Days 4-6 Weather SummaryMostly dry. Warm (max 23°C on Tue afternoon, min 18°C on Tue morning). Wind will be generally light. | ||||||||||||||||||||
Saturday 1 | Sunday 2 | Monday 3 | Tuesday 4 | Wednesday 5 | Thursday 6 | Friday 7 | |||||||||||||||
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 | NNW 6 | NNW 6 | NNW 6 | NW 6 | NW 5 | WNW 10 | WNW 10 | WNW 9 | WNW 9 | WNW 9 | WNW 8 | WNW 8 | WNW 8 | WNW 8 | NW 8 | WNW 8 | NW 7 | NW 7 | NW 4 |
Wave Graph | |||||||||||||||||||||
51 | 46 | 26 | 24 | 29 | 51 | 19 | 18 | 18 | 27 | 26 | 26 | 24 | 22 | 12 | 61 | 67 | 40 | 26 | 12 | 15 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | glassy | on | cross | on | on | cross-on | cross-on | on | off | glassy | cross-on | cross | cross-on | on | cross | cross | cross-on | glassy | glassy | on | cross-on |
High Tide | 7:14PM3.71m | 7:33AM3.44m | 7:47PM3.66m | 8:08AM3.39m | 8:23PM3.55m | 8:46AM3.30m | 9:03PM3.40m | 9:30AM3.18m | 9:53PM3.21m | 10:24AM3.04m | 10:56PM3.03m | 11:36AM2.95m | 00:20AM2.92m | ||||||||
Low Tide | 12:59PM0.37m | 1:25AM0.31m | 1:33PM0.40m | 1:59AM0.36m | 2:09PM0.48m | 2:36AM0.46m | 2:49PM0.60m | 3:18AM0.62m | 3:37PM0.76m | 4:09AM0.80m | 4:37PM0.91m | 5:14AM0.97m | 5:53PM1.00m | ||||||||
6:54 | — | — | 6:56 | — | — | 6:56 | — | — | 6:58 | — | — | 6:58 | — | — | 7:00 | — | — | 7:01 | — | — | |
— | — | 9:29 | — | — | 9:28 | — | — | 9:27 | — | — | 9:24 | — | — | 9:23 | — | — | 9:22 | — | — | 9:21 | |
mm | — | — | — | — | — | 1 | — | 1 | 5 | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 20 | 22 | 21 | 22 | 23 | 22 | 21 | 22 | 20 | 21 | 23 | 22 | 21 | 22 | 22 | 21 | 22 | 21 | 24 | 26 | 22 |
Feels °C | 21 | 22 | 21 | 22 | 23 | 21 | 22 | 22 | 22 | 23 | 23 | 22 | 22 | 23 | 23 | 23 | 22 | 21 | 25 | 27 | 21 |
Swell 1 Height (m) Direction Period (s) | NW 8 | NW 8 | NNW 6 | NNW 6 | NNW 6 | WNW 10 | NW 5 | NW 4 | NW 5 | WNW 9 | WNW 9 | WNW 9 | WNW 8 | WNW 8 | WNW 8 | WNW 8 | NW 8 | WNW 8 | NW 7 | NW 7 | NW 4 |
51 | 46 | 26 | 24 | 29 | 11 | 13 | 9 | 6 | 27 | 26 | 26 | 24 | 22 | 12 | 61 | 67 | 40 | 26 | 12 | 15 | |
Swell 2 Height (m) Direction Period (s) | W 9 | WNW 10 | WNW 9 | NW 7 | NW 7 | N 6 | WNW 10 | WNW 10 | WNW 10 | NW 5 | NW 7 | NNW 4 | NNW 4 | W 11 | NNW 4 | N 4 | — | N 4 | N 4 | WNW 10 | NW 7 |
6 | 10 | 16 | 8 | 8 | 1 | 19 | 18 | 18 | 6 | 2 | 2 | 3 | 2 | 2 | 3 | — | 10 | 4 | 9 | 2 | |
Swell 3 Height (m) Direction Period (s) | W 11 | W 9 | NW 8 | WNW 9 | WNW 9 | — | NNW 7 | NW 7 | NNW 7 | NNW 7 | — | NW 7 | — | — | WNW 10 | — | — | WNW 10 | WNW 10 | NW 8 | WNW 9 |
2 | 1 | 9 | 16 | 16 | — | 5 | 7 | 5 | 5 | — | 2 | — | — | 10 | — | — | 10 | 9 | 3 | 8 | |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | NW 6 | — | — | — | — | NNW 5 | — | — | NNW 4 | — | — | NNW 3 | — | — | NNW 4 | — |
— | — | — | — | — | 51 | — | — | — | — | 2 | — | — | 3 | — | — | 2 | — | — | 7 | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 1 | 87 | 17 | 177 | 583 | 17 | 347 | 347 | 21 | 21 | 534 | 325 | 333 | 490 | 21 | 6 | 197 | 1 | 21 | 610 | 393 |
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.











