Surf Forecasts:
Guethary - Les Alcyons/Avalanche surf forecast from 3 Aug 2026:
- Best quality surf: Friday 7 Aug, 2AM (local time) - 3ft (0.9m), 8s period, NNW swell with glassy winds.
- Most powerful swell: Monday 10 Aug, 8PM (local time) - 3.5ft (1.0m), 8s period, NW swell with 129 kJ wave energy.
- Next surfable swell (1★+): Friday 7 Aug, 2AM (local time) - 3ft (0.9m), 8s period with NNW 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 Friday (Aug 07) at 2AM. The primary swell is predicted to be 0.9m and 8s period with a secondary swell of 0.2m and 10s. 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 1.0m 8s and forecast to arrive on Monday (Aug 10) at 8PM. 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+) | 2AM (Fri 7th Aug) | 3ft (0.9m) 8s |
| Best Surf | 2AM (Fri 7th Aug) | 3ft (0.9m) 8s |
| Most Powerful | 8PM (Mon 10th Aug) | 3.5ft (1.0m) 8s |
Table - best surf conditions forecast for Guethary - Les Alcyons/Avalanche over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s take a look at what’s shaping up for the next couple of weeks.
Honestly, it’s a pretty flat and quiet stretch ahead. The first surfable day we see is Thursday morning, August 6th, but it’s only just hanging in there. The real standout doesn’t come until the second week, so you’ll need some patience.
Guethary - Les Alcyons/Avalanche is a reef break that takes a west swell and needs offshore from the southeast to be at its best. The water is running at 76°F, which is a solid 5°F warmer than normal for the time of year – that’s very unusual, so you’ll be in for a warm one if you get in.
Thursday morning, August 6th, we finally see a pulse of 3ft NW swell, but it’s short-period at 8 seconds. The wind is light cross-off from the ENE, so it’s clean. The combined energy is only moderate at 125, so it’s not much to write home about. It’s surfable, but very ordinary.
Friday morning, August 7th, the swell drops to 3ft from the NNW with a short 7-second period, but the wind goes glassy. That’s a huge positive for cleanliness, but the waves are tiny and weak.
Saturday morning, August 8th, is more of the same – glassy conditions with 2ft NNW swell, period down to 6 seconds. It’s clean but really small.
Then we hit a bit of a lull until August 11th. Tuesday morning, August 11th, we get 3ft NW swell, 7-second period, and glassy winds again. The combined energy is 124, so moderate. It’s clean, but still very small.
The one true standout in this whole forecast is the Saturday morning, August 15th. The swell picks up to 5ft from the NW, with a 6-second period. The wind is glassy again – that’s a major positive. The combined energy is 154, solidly moderate. This is the biggest swell of the window. For an expert reef break, this is the session to aim for. The 5ft height is manageable for experienced surfers, though it’s not going to be perfect given the short period. It’s clean, glassy, and the best on offer by a long shot. The downside? This is a consistent spot that can get crowded, and with the best conditions falling on a Saturday morning, expect it to be busy.
The rest of the days are mostly poor surf conditions with onshore or cross-onshore winds, or just not enough swell. It’s a tough run.
Rusty.
Short Range ForecastSome drizzle, heaviest during Wed night. Warm (max 23°C on Tue afternoon, min 19°C on Tue morning). Wind will be generally light. | Days 5-7 Weather SummarySome drizzle, heaviest during Sat night. Warm (max 27°C on Sat afternoon, min 18°C on Thu night). Wind will be generally light. | ||||||||||||||||||
Tuesday 4 | Wednesday 5 | Thursday 6 | Friday 7 | Saturday 8 | Sunday 9 | ||||||||||||||
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) | WNW 9 | WNW 9 | WNW 9 | WNW 9 | WNW 8 | WNW 8 | NW 10 | NW 8 | NW 8 | NNW 8 | NNW 7 | NNW 6 | NNW 6 | NNW 6 | NNW 6 | NW 12 | NW 11 | NW 10 | NW 9 |
Wave Graph  | |||||||||||||||||||
 kJ | 17 | 27 | 42 | 43 | 37 | 44 | 31 | 115 | 107 | 101 | 56 | 34 | 40 | 48 | 25 | 23 | 73 | 80 | 68 |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | glassy | on | cross-on | glassy | glassy | on | cross-on | cross | on | glassy | glassy | on | cross | cross | on | cross | glassy | on | cross-on |
High Tide | 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 | 1:03PM2.97m | 1:51AM2.98m | 2:25PM3.17m | 3:06AM3.18m | ||||||
Low Tide | 2:36AM0.46m | 2:49PM0.60m | 3:18AM0.62m | 3:37PM0.76m | 4:09AM0.80m | 4:37PM0.91m | 5:14AM0.97m | 5:53PM1.00m | 6:34AM1.05m | 7:20PM0.94m | 7:56AM0.96m | 8:38PM0.72m | |||||||
 | |  |  | | |  |  | |  | | | | | | | | | | |
 | — | 6:58 | — | — | 6:58 | — | — | 7:00 | — | — | 7:01 | — | — | 7:03 | — | — | 7:03 | — | — |
 | 9:27 | — | — | 9:24 | — | — | 9:23 | — | — | 9:22 | — | — | 9:21 | — | — | 9:20 | — | — | 9:19 |
mm | — | — | — | — | — | — | 1 | — | — | — | — | — | — | — | — | 1 | — | — | 2 |
Temp °C | 22 | 22 | 23 | 22 | 21 | 22 | 22 | 19 | 21 | 20 | 20 | 22 | 21 | 23 | 27 | 23 | 24 | 24 | 22 |
Feels °C | 24 | 24 | 23 | 22 | 23 | 23 | 22 | 19 | 20 | 19 | 20 | 21 | 21 | 22 | 26 | 22 | 26 | 24 | 22 |
Swell 1 Height (m) Direction Period (s) | WNW 9 | WNW 9 | WNW 9 | WNW 9 | WNW 8 | WNW 8 | WNW 7 | NW 8 | NW 8 | NNW 8 | NNW 7 | NNW 6 | NNW 6 | NNW 6 | NNW 6 | NNW 5 | NNW 5 | NW 10 | NW 9 |
| kJ | 17 | 27 | 42 | 43 | 37 | 44 | 31 | 115 | 107 | 101 | 56 | 34 | 40 | 48 | 25 | 21 | 24 | 80 | 68 |
Swell 2 Height (m) Direction Period (s) | NW 7 | NW 7 | — | NNW 3 | NW 11 | NW 11 | NW 10 | WNW 10 | WNW 10 | WNW 10 | WNW 10 | WNW 10 | WNW 9 | W 9 | W 9 | NW 12 | NW 11 | W 9 | W 8 |
| kJ | 8 | 8 | — | 1 | 5 | 5 | 24 | 11 | 10 | 10 | 9 | 9 | 8 | 2 | 2 | 23 | 73 | 2 | 1 |
Swell 3 Height (m) Direction Period (s) | NNW 4 | — | — | NW 7 | — | — | W 10 | — | — | — | — | — | — | — | NW 11 | W 9 | W 9 | — | — |
| kJ | 1 | — | — | 2 | — | — | 2 | — | — | — | — | — | — | — | 4 | 2 | 2 | — | — |
Wind waves Height (m) Direction Period (s) | — | — | NNW 7 | — | — | — | N 4 | — | — | — | — | — | — | — | — | WSW 3 | — | NW 5 | WNW 4 |
| kJ | — | — | 5 | — | — | — | 2 | — | — | — | — | — | — | — | — | 1 | — | 14 | 23 |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 485 | 21 | 54 | 534 | 1 | 3 | 490 | 6 | 0 | 87 | 0 | 1 | 325 | 31 | 578 | 490 | 31 | 1 | 196 |
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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