Surf Forecasts:
Guethary - Les Alcyons/Avalanche surf forecast from 29 Jul 2026:
- Most powerful swell: Wednesday 29 Jul, 8PM (local time) - 2.5ft (0.8m), 9s period, NW swell with 97 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 0.8m 9s and forecast to arrive on Wednesday (Jul 29) at 8PM. Winds are predicted to be cross-onshore at the time the swell arrives.
| Wave Type | Time (CEST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 8PM (Wed 29th Jul) | 2.5ft (0.8m) 9s |
Table - best surf conditions forecast for Guethary - Les Alcyons/Avalanche over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s get into it for the Basque Coast.
Looking at the whole 16-day window, I gotta be straight with you – it’s a tough one. We’re looking at a long, dry spell with nada to get excited about for the first week and a half. The only spot that’s even on the radar is Guethary - Les Alcyons/Avalanche, and even then, it’s mostly a story of waiting.
The first real flicker of hope doesn’t show up until the morning of Friday, August 7th. For days before that, it’s all tiny, weak swell with poor conditions. The water temp is sitting at a balmy 76°F, which is *much warmer than normal* for this time of year, but that’s about the only nice thing to say.
So, the standout in this entire forecast is the morning of Friday, August 7th at Guethary - Les Alcyons/Avalanche. We’re looking at a 4ft swell from the WNW, with a short period of 8 seconds. The combined energy is a moderate 222. The key here is the wind: a light offshores from the NE, going cross-shore, and it’s only a 3 mph breeze. That’s going to keep the surface clean. This is an expert reef break that’s consistent, so you’ll need your wits about you, but it might be the only window where the stars align for a session. Crowds are likely here, so get there early.
The following morning, Saturday, August 8th, is your second look. The swell drops to 3ft from the WNW, with a period of 8 seconds and a moderate energy of 147. But the wind goes glassy from the east at 3 mph. It’s "surfable waves but very ordinary conditions," so it’s a smaller, cleaner option if you missed Friday. After that, the wind picks up and the swell drops off again, shutting it down for the rest of the run.
The long-range stuff around August 10th looks promising on paper with a longer period swell, but the onshore winds ruin it. Stick to that Friday morning, August 7th, if you can.
Rusty.
Short Range ForecastMostly dry. Warm (max 26°C on Wed afternoon, min 19°C on Thu morning). Wind will be generally light. | Days 5-7 Weather SummaryMostly dry. Warm (max 23°C on Sun afternoon, min 17°C on Sat night). Wind will be generally light. | |||||||||||||||||||
Wed 29 | Thursday 30 | Friday 31 | Saturday 1 | Sunday 2 | Monday 3 | Tuesday 4 | ||||||||||||||
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 9 | NW 9 | NW 8 | NW 8 | NW 8 | NW 8 | NW 8 | NW 8 | NW 8 | NW 6 | NNW 6 | NW 6 | NW 6 | NW 6 | NW 5 | NW 5 | NW 5 | NW 5 | NNW 5 | NNW 6 |
Wave Graph  | ||||||||||||||||||||
 kJ | 135 | 93 | 57 | 86 | 84 | 66 | 64 | 57 | 93 | 38 | 25 | 34 | 33 | 39 | 27 | 31 | 22 | 17 | 18 | 22 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | cross-on | on | on | on | on | on | on | on | on | glassy | cross-on | on | cross-on | cross-on | on | cross | glassy | cross-on | cross-off |
High Tide | 5:37PM3.54m | 5:57AM3.36m | 6:10PM3.65m | 6:29AM3.42m | 6:42PM3.71m | 7:01AM3.45m | 7:14PM3.71m | 7:33AM3.44m | 7:47PM3.66m | 8:08AM3.39m | 8:23PM3.55m | 8:46AM3.30m | 9:03PM3.40m | |||||||
Low Tide | 11:45PM0.45m | 11:53AM0.47m | 00:19AM0.35m | 12:26PM0.39m | 00:52AM0.31m | 12:59PM0.37m | 1:25AM0.31m | 1:33PM0.40m | 1:59AM0.36m | 2:09PM0.48m | 2:36AM0.46m | 2:49PM0.60m | 3:18AM0.62m | |||||||
 |  |  | |  | | | | | | | | | |  | | | | | | |
 | — | — | 6:52 | — | — | 6:54 | — | — | 6:54 | — | — | 6:56 | — | — | 6:56 | — | — | 6:58 | — | — |
 | — | 9:31 | — | — | 9:30 | — | — | 9:30 | — | — | 9:29 | — | — | 9:28 | — | — | 9:27 | — | — | 9:24 |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 26 | 22 | 21 | 22 | 22 | 20 | 22 | 21 | 21 | 22 | 21 | 21 | 23 | 22 | 21 | 22 | 21 | 21 | 23 | 22 |
Feels °C | 27 | 22 | 22 | 22 | 23 | 21 | 22 | 22 | 21 | 22 | 21 | 21 | 23 | 22 | 21 | 22 | 21 | 22 | 23 | 22 |
Swell 1 Height (m) Direction Period (s) | NW 9 | NW 9 | NW 8 | NW 8 | NW 8 | NW 8 | NW 8 | NW 8 | NW 8 | NW 6 | NNW 6 | NW 6 | NW 6 | NW 6 | WNW 10 | NW 5 | NW 5 | NW 5 | NNW 5 | NNW 6 |
| kJ | 135 | 93 | 57 | 86 | 84 | 66 | 64 | 57 | 93 | 38 | 25 | 34 | 33 | 39 | 10 | 31 | 22 | 16 | 18 | 22 |
Swell 2 Height (m) Direction Period (s) | — | — | — | — | — | — | — | NW 9 | W 9 | NW 8 | NW 7 | WNW 9 | WNW 9 | WNW 9 | NNW 7 | WNW 10 | WNW 9 | WNW 9 | WNW 9 | WNW 9 |
| kJ | — | — | — | — | — | — | — | 3 | 2 | 21 | 19 | 8 | 8 | 8 | 5 | 9 | 17 | 17 | 16 | 16 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | W 12 | W 11 | WNW 9 | WNW 9 | — | — | W 11 | — | N 6 | — | NNW 7 | NNW 7 | — |
| kJ | — | — | — | — | — | — | — | 3 | 2 | 8 | 16 | — | — | 2 | — | 3 | — | 5 | 5 | — |
Wind waves Height (m) Direction Period (s) | — | WNW 4 | WNW 4 | — | — | — | — | — | — | — | — | — | — | — | NW 5 | — | — | — | — | — |
| kJ | — | 8 | 13 | — | — | — | — | — | — | — | — | — | — | — | 27 | — | — | — | — | — |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 12 | 91 | 196 | 197 | 87 | 17 | 625 | 197 | 122 | 87 | 1 | 177 | 197 | 31 | 47 | 560 | 31 | 31 | 606 | 21 |
Best forecast wave conditions in La Cote Basque | ||||||||||||||||||||
Best forecast wave conditions in France | ||||||||||||||||||||
Header Global | ||||||||||||||||||||
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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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