Surf Forecasts:
Guethary - Les Alcyons/Avalanche surf forecast from 20 Jul 2026:
- Most powerful swell: Sunday 26 Jul, 8PM (local time) - 8ft (2.5m), 8s period, WNW swell with 804 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 2.5m 8s and forecast to arrive on Sunday (Jul 26) at 8PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.3m 5s period and expected on Saturday (Jul 25) at 5AM.
| Wave Type | Time (CEST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 8PM (Sun 26th Jul) | 8ft (2.5m) 8s |
Table - best surf conditions forecast for Guethary - Les Alcyons/Avalanche over the next 16 days.
The Lowdown
G'day, Rusty here. Look, I've gotta be straight with you – this forecast is a tough one for Guethary. The whole 16-day window is a bit of a write-off for decent surf. We're looking at a long stretch of days where the conditions are just not happening, so don't get your hopes up.
Starting off on Monday the 20th of July, it's glassy and tiny, but the swell is weak and messy with a combined energy of only 70. It's a no-go. That sets the tone for the rest of the week. Through Tuesday, Wednesday, Thursday, and Friday, we've got nothing but small, weak swell (under 3ft) and poor surf conditions. The water temp is a notable 77°, which is much warmer than normal for this time of year, but that's about the only positive.
Then we hit the weekend of the 25th and 26th of July. The swell does pick up a bit, with some 6ft to 8ft energy coming from the WNW, but the wind is a problem. It's a strong cross-onshore, blowing 15 to 22 mph, making it a choppy, lumpy mess. The combined energy hits 661 on the Sunday afternoon, which is strong, but with that wind, it's a complete write-off for paddle surfing. This setup honestly looks more interesting for kite surfing.
The following week, from the 27th of July through to the 4th of August, is a bit of a mixed bag but mostly poor. The Monday sees some leftover size (6ft) but it's onshore and messy. By Tuesday the 28th, it drops to 4ft and the wind is still a problem. Wednesday the 29th and Thursday the 30th of July do offer a glimmer of hope: the mornings are glassy with a 3ft NW swell at a 9-second period, and the combined energy is moderate (126 and 166). It's surfable, but very ordinary. The break is an expert-level reef, so it's not for the faint-hearted, and it can get crowded often. The optimum swell is from the west, so this NW swell isn't ideal.
After that, it fades again into tiny, poor conditions right through to the 4th of August. There's a brief moment on the morning of the 2nd of August with a clean cross-offshore wind, but the swell is only 3ft. It's a long, blank run with very little to offer. The only real standout in this whole period is the glassy mornings on the 29th and 30th of July, but even then, it's just ordinary waves. Not a classic forecast, folks.
Rusty.
Short Range ForecastMostly dry. Warm (max 29°C on Wed afternoon, min 18°C on Wed morning). Wind will be generally light. | Days 4-6 Weather SummaryModerate rain (total 14mm), heaviest on Sat night. Warm (max 29°C on Thu afternoon, min 19°C on Fri morning). Winds increasing (calm on Fri morning, fresh winds from the W by Sat afternoon). | ||||||||||||||||||||
Monday 20 | Tuesday 21 | Wednesday 22 | Thursday 23 | Friday 24 | Saturday 25 | Sunday 26 | |||||||||||||||
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) | NNW 6 | NNW 7 | NNW 7 | NNW 7 | N 7 | NNW 6 | NNW 6 | NNW 6 | NNW 6 | NNW 6 | NNW 6 | NNW 6 | NNW 6 | NNW 5 | NNW 5 | W 5 | WNW 7 | NW 6 | WNW 7 | WNW 8 | NW 8 |
Wave Graph  | |||||||||||||||||||||
 kJ | 50 | 58 | 141 | 93 | 92 | 104 | 41 | 36 | 95 | 38 | 30 | 61 | 25 | 16 | 20 | 59 | 317 | 182 | 332 | 622 | 382 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | glassy | on | cross | cross-on | on | cross | cross | on | cross | cross | on | cross | glassy | on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | on |
High Tide | 9:43AM3.19m | 10:03PM3.26m | 10:31AM2.99m | 10:55PM2.98m | 11:27AM2.83m | 11:58PM2.77m | 12:35PM2.74m | 1:13AM2.67m | 1:48PM2.75m | 2:26AM2.70m | 2:52PM2.86m | 3:24AM2.81m | 3:43PM3.02m | 4:10AM2.97m | |||||||
Low Tide | 3:40PM0.70m | 4:12AM0.78m | 4:32PM0.94m | 5:04AM1.02m | 5:33PM1.14m | 6:05AM1.20m | 6:43PM1.24m | 7:14AM1.27m | 7:55PM1.23m | 8:20AM1.23m | 8:57PM1.11m | 9:16AM1.10m | 9:48PM0.94m | ||||||||
 | |  | | | | | | | | | | | | | |  |  |  |  |  | |
 | 6:43 | — | — | 6:43 | — | — | 6:45 | — | — | 6:46 | — | — | 6:47 | — | — | 6:48 | — | — | 6:48 | — | — |
 | — | — | 9:40 | — | — | 9:39 | — | — | 9:38 | — | — | 9:38 | — | — | 9:37 | — | — | 9:37 | — | — | 9:36 |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 3 | 11 | 2 | — | 6 |
Temp °C | 23 | 24 | 23 | 22 | 24 | 23 | 24 | 29 | 26 | 25 | 29 | 26 | 25 | 27 | 24 | 22 | 22 | 21 | 20 | 21 | 21 |
Feels °C | 25 | 24 | 22 | 22 | 23 | 21 | 23 | 26 | 26 | 25 | 27 | 26 | 25 | 27 | 23 | 18 | 18 | 19 | 17 | 18 | 19 |
Swell 1 Height (m) Direction Period (s) | NNW 6 | NNW 7 | NNW 7 | NNW 7 | N 7 | NNW 6 | NNW 6 | WNW 10 | NNW 6 | NNW 6 | NNW 6 | NNW 6 | NNW 6 | NNW 5 | NNW 5 | N 5 | N 6 | NW 10 | WNW 7 | NW 12 | NW 8 |
| kJ | 50 | 58 | 141 | 93 | 92 | 104 | 41 | 9 | 95 | 38 | 30 | 61 | 25 | 16 | 20 | 8 | 15 | 4 | 332 | 39 | 382 |
Swell 2 Height (m) Direction Period (s) | NW 8 | NW 8 | NW 12 | W 4 | WNW 11 | WNW 10 | WNW 10 | — | WNW 10 | WNW 10 | WNW 9 | WNW 9 | NW 9 | NW 9 | WNW 8 | — | NW 11 | — | NW 13 | — | NW 11 |
| kJ | 16 | 10 | 6 | 2 | 11 | 10 | 10 | — | 9 | 9 | 8 | 8 | 3 | 3 | 7 | — | 5 | — | 7 | — | 94 |
Swell 3 Height (m) Direction Period (s) | NW 10 | NW 13 | — | WNW 11 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | 4 | 6 | — | 12 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | NNW 6 | — | — | — | — | — | — | W 3 | W 5 | WNW 7 | NW 6 | — | WNW 8 | — |
| kJ | — | — | — | — | — | — | — | 36 | — | — | — | — | — | — | 3 | 59 | 317 | 182 | — | 622 | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 1 | 197 | 12 | 26 | 87 | 13 | 1 | 87 | 13 | 1 | 197 | 10 | 111 | 1805 | 161 | 612 | 1601 | 63 | 12 | 403 | 147 |
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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