Trearddur Bay (Holy Island) Surf Break

Lat Long: 53.28° N 4.62° W

Trearddur Bay (Holy Island) Surf Forecast and Surf Report

Issued: 12 pm 20 Aug 2026 (local time)

Forecast update in  hr  min

Today's Trearddur Bay (Holy Island) sea temperature is
17.6° C
1.9° 

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 20 Aug 2026:

  • Best quality surf: Thursday 27 Aug, 1AM (local time) - 3.5ft (1.1m), 8s period, SW swell with cross-offshore winds.
  • Most powerful swell: Wednesday 26 Aug, 7PM (local time) - 5ft (1.6m), 7s period, SSW swell with 236 kJ wave energy.
  • Next surfable swell (1★+): Thursday 27 Aug, 1AM (local time) - 3.5ft (1.1m), 8s period with SW swell.

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

The surf forecast for Trearddur Bay (Holy Island) over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Thursday (Aug 27) at 1AM. The primary swell is predicted to be 1.1m and 8s period. The wind is predicted to be cross-offshore as the swell arrives.

The most powerful waves expected at Trearddur Bay (Holy Island) in the next 16 days are 1.6m 7s and forecast to arrive on Wednesday (Aug 26) at 7PM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.2m 5s period and expected on Friday (Aug 21) at 1AM.

Wave TypeTime (BST) & Date Wave Height & Period
Next good surf (1 star+) 1AM (Thu 27th Aug)3.5ft (1.1m) 8s
Best Surf 1AM (Thu 27th Aug)3.5ft (1.1m) 8s
Most Powerful 7PM (Wed 26th Aug)5ft (1.6m) 7s

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


The Lowdown

Alright, folks, Rusty here. Let's talk about the next couple weeks for Trearddur Bay. It’s going to be a test of patience, I'm not gonna lie. Right now, we're looking at a serious flat spell, and it’s going to be a while before we see any real waves.

The water is sitting at 64°F, which is a touch warmer than normal for the season, so you won't be freezing on your board.

The first week, from Thursday the 20th through Monday the 25th, is a complete write-off. We're talking swell heights at a measly 0.3ft, with periods all over the shop and combined energy readings in the tank—we're seeing values like 24, 18, and even 4. It's flat out dead. No energy, no shape, nothing. You'd be better off polishing your board or finding a new hobby for a few days. This is a proper drought.

We get a small pulse mid-week, but it's not much. Wednesday the 26th shows a bit of swell in the morning, with 3ft from the S, but the period is a weak 5 seconds, so it won't hold together. The afternoon picks up a little to 6ft from the SSW, and the energy jumps to 237, but it's still going to be a messy and uninspiring surf. On Thursday morning the 27th, we get a brief moment of glass with light easterly winds and a clean 2ft from the SSW. It’s surfable, but it's not going to get the heart pumping.

Now, here’s the one to circle on your calendar: Friday the 28th. This is the standout of the entire window. The morning shows a building swell, reaching 7ft from the SSW with energy at 309. But the south wind is going to be blowing 30 km/h, chopping it up pretty good. The real deal is the afternoon. The swell pushes up to a solid 10ft from the SSW, and the energy explodes to 1025. That’s serious, heavy ocean energy. This is big, powerful stuff. That kind of size is not for beginners. This is expert-only territory. The cross-shore wind will add some chaos to it. If you're not a seasoned big-wave surfer, you'll be on the beach. Honestly, the way this is shaping up, it might be more of a kite-surfing day than a paddle-surfing day.

After that pulse, it fades out. Saturday the 29th has a clean, glassy morning with a small 3ft wave from the SW. That will be a nice, calm session for smaller boards. But the windows of opportunity are short.

From Sunday the 30th into the first week of September, it just dies off again. Swell drops back to 0.7ft and 1ft, with energy readings of 16 or less. It’s back to the same flat, weak pattern. The 2nd of September shows a little bump to 4ft from the SW, but it's nothing special, and the energy is only 115. The second week is pretty forgettable.

So, here’s the deal: the only true highlight is Friday the 28th afternoon. It’s a short, sharp, and powerful swell, but it comes with a warning. If you've got the skills and the right board for heavy water, that's your moment. For the rest of us, it’s a waiting game. This flat spell is a stubborn one, but it can't last forever.

Rusty

Short Range Forecast

Light rain (total 8mm), mostly falling on Thu morning. Very mild (max 16°C on Fri afternoon, min 13°C on Thu night). Winds decreasing (fresh winds from the N on Thu morning, light winds from the NNE by Sat night).

Days 4-6 Weather Summary

Mostly dry. Warm (max 21°C on Mon afternoon, min 14°C on Sun morning). Wind will be generally light.

Thursday
20
Friday
21
Saturday
22
Sunday
23
Monday
24
Tuesday
25
Wednesday
26
AM
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
1
Swell
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Wave
Height (m)
Direction
Period (s)
0.5
SW
6
0.4
SW
6
0.1
SW
14
0.1
SW
14
0.1
SW
13
0.1
SW
13
0.1
SW
15
0.1
SW
15
0.1
SW
15
0.1
SW
14
0.1
SW
14
0.1
SW
14
0.1
SW
14
0.1
SW
13
0.1
SW
13
0.2
SSE
4
0.4
SE
4
0.5
S
3
1
S
5
1.7
SSW
7
1.1
SW
8
Wave Graph
Metric surfscale
Energy kJ
16
10
8
7
7
7
8
8
8
8
7
7
8
7
7
3
7
5
59
234
133
Wind (km/h)
30
N
30
N
25
NNW
10
NNE
20
NNE
20
N
20
NNW
15
NNW
15
N
5
NNW
10
NNW
15
ENE
10
ENE
10
WNW
20
ESE
20
E
20
E
25
E
15
SSE
5
SSE
5
NNW
Wind State
cross-off
cross-off
cross-off
off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
cross
cross-off
cross-off
cross-off
cross-off
cross-on
cross
cross-off
High Tide
4:23PM4.44m
4:52AM4.29m
5:32PM4.26m
6:23AM4.10m
7:07PM4.27m
8:04AM4.17m
8:27PM4.49m
9:08AM4.41m
9:19PM4.79m
9:52AM4.67m
9:59PM5.08m
10:26AM4.89m
10:33PM5.32m
Low Tide
10:14AM1.98m
10:37PM2.18m
11:17AM2.31m
11:58PM2.41m
12:45PM2.45m
1:37AM2.37m
2:08PM2.34m
2:47AM2.11m
3:05PM2.09m
3:35AM1.78m
3:46PM1.80m
4:11AM1.47m
4:21PM1.52m
rain showers
part cloud
rain showers
rain showers
clear
clear
clear
clear
clear
clear
clear
clear
part cloud
part cloud
part cloud
cloud
part cloud
part cloud
part cloud
light rain
rain showers
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
6:05
6:07
6:09
6:11
6:13
6:13
6:16
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
8:36
8:34
8:31
8:29
8:27
8:24
8:22
 mm
3
2
3
1
27
Temp °C
15
15
15
15
16
14
14
15
15
15
16
16
20
21
20
17
21
19
20
21
16
Feels °C
10
9
10
11
12
9
10
13
13
13
14
13
19
19
14
13
17
16
18
21
16
  • 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 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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