Trearddur Bay (Holy Island) Surf Break

Lat Long: 53.28° N 4.62° W

Trearddur Bay (Holy Island) Surf Forecast and Surf Report

Issued: 6 pm 10 Aug 2026 (local time)

Forecast update in  hr  min

Today's Trearddur Bay (Holy Island) sea temperature is
16.9° C
1.3° 

Trearddur Bay (Holy Island) surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.


Trearddur Bay (Holy Island) surf forecast from 10 Aug 2026:

  • Most powerful swell: Friday 14 Aug, 1AM (local time) - 2.5ft (0.8m), 5s period, SW swell with 31 kJ wave energy.

Best Forecast Surf Conditions for Trearddur Bay (Holy Island) this week:

The most powerful waves expected at Trearddur Bay (Holy Island) in the next 16 days are 0.8m 5s and forecast to arrive on Friday (Aug 14) at 1AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.6m 4s period and expected on Saturday (Aug 15) at 1AM.

Wave TypeTime (BST) & Date Wave Height & Period
Next good surf (1 star+)--
Best Surf--
Most Powerful 1AM (Fri 14th Aug)2.5ft (0.8m) 5s

Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.


The Lowdown

Right then, let’s have a look at the 16-day picture for Trearddur Bay (Holy Island). Honestly, it’s a bit of a tough watch. The data shows a whole lot of small, weak swell and tricky wind for the first couple of weeks. There’s a real gap of poor conditions before we get a couple of more interesting days right at the end of the window. Let’s break it down.

The water temp is sitting at 62°F, which is a touch warmer than normal for this time of year, so your wetsuit might be a bit more comfortable than usual.

Monday, the 10th of August, kicks off with a tiny 1.0ft SW swell at 6 seconds. Combined energy is only 5, so it’s barely a ripple. The wind is a cross-off from the N at 9 mph, which keeps the surface clean, but there’s just no power to work with. Tuesday and Wednesday are even smaller, with onshore and cross-onshore breezes making it messy. The period on Wednesday morning is a long 12 seconds, but the swell height is only 0.3ft, so it’s just a tease.

We get a bit of a pulse on the 14th and 15th. Friday the 14th morning sees a 2ft NW swell, energy of 27, but it’s a cross-shore wind at 12 mph, so it’s choppy. Saturday the 15th morning is a bit better: a 3ft NW swell, energy of 30, with a cross-off breeze from the NW at 16 mph. That’s clean, but the swell is still short period at 4 seconds, so it’s a bit weak and lacking shape. Not a standout.

The next week stays pretty flat and poor. There’s a day on the 19th of August with a very long period, 16 seconds, from the SW, but it’s only 0.3ft. The wind is glassy in the morning, which is lovely, but there’s nothing to ride.

The real interest comes on the 21st and 22nd of August. Friday the 21st afternoon brings a 6ft SSW swell, energy of 266, so it’s got some moderate power. The problem is the wind is a strong cross-on from the SSW at 25 mph, which is going to tear it to pieces. That’s more of a kite day than a paddle day for most.

The standout of the whole outlook is Saturday, the 22nd of August. This is the one to have your eye on. The morning shows a 8ft WNW swell, with a combined energy of 461 – that’s *strong*. The period is 6 seconds, so it’s a wind swell, not a groundswell, but it’s got plenty of push. The wind is a cross-shore from the NW at 16 mph, which will be a bit bumpy. The afternoon gets even better: an 8ft WNW swell, energy of 620, and the wind drops to a light 6 mph cross-shore from the NW. That’s a whole lot of wave energy and clean conditions. At 8ft, this is firmly in the "experts only" zone – it’s going to be big and powerful. If you’re experienced and you’re looking for a proper session, this is your window. The swell direction is from the WNW, which is a bit off the optimum SW, but with that much energy, it’ll still wrap in.

After that, it fades quickly. The 23rd and 24th are back to tiny, long-period leftovers that won’t break properly. The 25th of August shows a little 3ft SSW swell, energy of 51, with clean cross-off winds, but it’s a small, short-period wave.

So, bottom line: the first two weeks are a write-off. The only real chance for a decent wave is Saturday the 22nd of August. That afternoon session is your best bet, but it’s for the experienced crew.

Rusty.

Short Range Forecast

Mostly dry. Warm (max 24°C on Wed afternoon, min 15°C on Mon afternoon). Wind will be generally light.

Days 5-7 Weather Summary

Light rain (total 2mm), mostly falling on Sun morning. Warm (max 21°C on Thu afternoon, min 13°C on Sun morning). Wind will be generally light.

Mon
10
Tuesday
11
Wednesday
12
Thursday
13
Friday
14
Saturday
15
Sunday
16
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
Rating
(10 max)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Swell
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Wave
Height (m)
Direction
Period (s)
0.3
SW
6
0.2
SSW
6
0.2
SSW
6
0.3
S
3
0.1
S
11
0.1
SW
12
0.1
SW
12
0.1
SW
10
0.1
SW
10
0.1
SW
11
0.8
SW
5
0.7
NW
4
0.4
WSW
4
0.2
SSW
5
0.9
NW
4
0.4
WNW
4
0.4
W
3
0.3
SW
5
0.1
SW
5
0.1
SW
4
Wave Graph
Metric surfscale
Energy kJ
5
4
4
1
2
5
6
4
4
4
31
19
5
3
28
5
3
4
1
1
Wind (km/h)
15
N
20
ENE
10
S
15
SW
10
SE
15
S
10
WNW
10
SSE
15
SSW
10
WSW
15
S
20
NW
15
NW
20
NW
25
NW
15
WNW
10
NW
10
NNW
15
NNW
15
NNE
Wind State
cross-off
off
cross-on
on
cross
cross-on
cross-on
cross-on
on
on
cross-on
cross
cross
cross
cross-off
cross-on
cross
cross-off
cross-off
cross-off
High Tide
9:30PM5.16m
10:01AM5.19m
10:21PM5.51m
10:50AM5.42m
11:07PM5.78m
11:35AM5.56m
11:49PM5.94m
12:16PM5.58m
00:30AM5.96m
12:56PM5.52m
1:10AM5.85m
1:35PM5.37m
1:49AM5.63m
Low Tide
3:41AM1.10m
4:01PM1.21m
4:33AM0.72m
4:48PM0.94m
5:19AM0.45m
5:32PM0.74m
6:02AM0.32m
6:14PM0.67m
6:44AM0.35m
6:54PM0.71m
7:25AM0.53m
7:34PM0.87m
part cloud
part cloud
clear
clear
part cloud
part cloud
part cloud
clear
part cloud
part cloud
part cloud
cloud
part cloud
part cloud
part cloud
part cloud
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rain showers
cloud
clear
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
5:50
5:52
5:54
5:54
5:56
5:58
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
8:57
8:54
8:52
8:51
8:49
8:46
8:45
 mm
2
Temp °C
16
17
20
21
20
22
24
23
21
21
19
15
17
17
14
16
16
14
14
14
Feels °C
13
14
16
18
19
19
22
21
20
21
17
12
15
14
10
14
14
12
12
12
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  • 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 Trearddur Bay (Holy Island) Surf forecast

The above surf forecast table for Trearddur Bay (Holy Island) provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Trearddur Bay (Holy Island) can be found by selecting the local surf guide option on the grey menu. Our Trearddur Bay (Holy Island) 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 (Trearddur Bay (Holy Island)) 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 Trearddur Bay (Holy Island) 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.

Are you planning a holiday in Anglesy? If you are looking for accommodation near Trearddur Bay (Holy Island), camping, hotels and holiday cottages in Anglesy, consider staying in Holyhead which is 4 km (2 miles) away. Other places in and around Anglesy where you can find information about places to rent, and car hire include Anglesey which is 7 km (4 miles) away, Bangor, Porthmadog and Llandudno.

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