Guethary - Les Alcyons/Avalanche Surf Break

Lat Long: 43.43° N 1.62° W

Guethary - Les Alcyons/Avalanche Surf Forecast and Surf Report

Issued: 7 pm 17 Sep 2026 (local time)

Forecast update in  hr  min

Today's Guethary - Les Alcyons/Avalanche sea temperature is
22.4°C
2.3° 

Guethary - Les Alcyons/Avalanche surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.


Guethary - Les Alcyons/Avalanche surf forecast from 18 Sep 2026:

  • Best quality surf: Saturday 19 Sep, 2AM (local time) - 8ft (2.4m), 13s period, NW swell with glassy winds.
  • Most powerful swell: Friday 18 Sep, 11PM (local time) - 8ft (2.4m), 13s period, NW swell with 2,035 kJ wave energy.
  • Next surfable swell (1★+): Saturday 19 Sep, 2AM (local time) - 8ft (2.4m), 13s period with NW 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 Saturday (Sep 19) at 2AM. The primary swell is predicted to be 2.4m and 13s period. 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 2.4m 13s and forecast to arrive on Friday (Sep 18) at 11PM. Winds are predicted to be cross-onshore at the time the swell arrives.

Wave TypeTime (CEST) & Date Wave Height & Period
Next good surf (1 star+) 2AM (Sat 19th Sep)8ft (2.4m) 13s
Best Surf 2AM (Sat 19th Sep)8ft (2.4m) 13s
Most Powerful11PM (Fri 18th Sep)8ft (2.4m) 13s

Table - best surf conditions forecast for Guethary - Les Alcyons/Avalanche over the next 16 days.


Short Range Forecast

Mostly dry. Warm (max 24°C on Sun afternoon, min 14°C on Sat morning). Wind will be generally light.

Days 5-7 Weather Summary

Mostly dry. Warm (max 23°C on Mon afternoon, min 16°C on Wed morning). Wind will be generally light.

Friday
18
Saturday
19
Sunday
20
Monday
21
Tuesday
22
Wednesday
23
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
Rating
(10 max)
1
1
2
4
4
2
3
3
1
2
3
1
2
3
0
2
2
0
2
Swell
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Wave
Height (m)
Direction
Period (s)
1.3
NW
10
1.3
NW
10
2.1
NW
13
2.4
NW
13
2.1
NW
13
1.8
NW
13
1.6
NW
12
1.7
NW
12
1.6
NW
11
1.7
NW
11
1.7
NW
11
1.6
NW
11
1.5
NW
11
1.4
NW
12
1.2
NW
12
1.1
NW
11
1
NW
11
0.9
NW
11
1.4
NW
14
Wave Graph
Metric surfscale
Energy kJ
315
296
1423
2005
1468
1052
736
760
640
696
721
675
544
546
396
273
224
163
846
Wind (km/h)
5
W
10
WSW
15
NNW
5
ENE
5
ENE
15
N
5
SSW
5
ENE
10
NNW
10
SW
0
N
10
NNW
10
SW
5
NNE
10
NW
5
SW
5
NE
10
NNW
10
SW
Wind State
cross-on
cross-on
on
glassy
cross-off
cross-on
glassy
glassy
cross-on
cross
glassy
on
cross
glassy
on
cross-off
glassy
on
cross
High Tide
9:09PM2.84m
9:27AM2.82m
10:03PM2.57m
10:34AM2.60m
11:37PM2.40m
12:24PM2.53m
1:30AM2.46m
1:57PM2.69m
2:36AM2.66m
2:51PM2.94m
3:19AM2.91m
3:30PM3.21m
3:53AM3.17m
Low Tide
3:18AM1.17m
3:54PM1.23m
4:17AM1.42m
5:12PM1.43m
5:47AM1.55m
6:54PM1.44m
7:23AM1.46m
8:11PM1.25m
8:27AM1.23m
9:00PM0.98m
9:12AM0.95m
9:39PM0.70m
part cloud
part cloud
part cloud
clear
clear
clear
clear
clear
clear
clear
clear
clear
clear
clear
clear
clear
clear
clear
clear
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
7:48
7:48
7:50
7:50
7:52
7:54
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
8:14
8:12
8:09
8:07
8:06
8:05
8:02
 mm
Temp °C
19
19
19
18
16
21
19
19
24
21
20
23
20
19
21
20
20
22
20
Feels °C
19
19
18
18
16
20
19
20
23
21
21
22
20
20
20
18
20
21
20
  • Map Icons:
  • Break
  • Live Wave Height (m)
  • Live Wind Speed (km/h)
  • Surf Rating (10 Max)
  • Ocean Swells (m)
  • Wind Speed (km/h)
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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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