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 am 21 Aug 2026 (local time)

Forecast update in  hr  min

Today's Trearddur Bay (Holy Island) sea temperature is
17.4° C
1.7° 

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 21 Aug 2026:

  • Best quality surf: Thursday 27 Aug, 10AM (local time) - 3ft (0.9m), 8s period, SSW swell with glassy winds.
  • Most powerful swell: Wednesday 26 Aug, 7PM (local time) - 4.5ft (1.3m), 7s period, SSW swell with 163 kJ wave energy.
  • Next surfable swell (1★+): Thursday 27 Aug, 10AM (local time) - 3ft (0.9m), 8s period with SSW 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 10AM. The primary swell is predicted to be 0.9m and 8s period. The wind is predicted to be glassy as the swell arrives.

The most powerful waves expected at Trearddur Bay (Holy Island) in the next 16 days are 1.3m 7s and forecast to arrive on Wednesday (Aug 26) at 7PM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.8m 5s period and expected on Friday (Aug 21) at 1PM.

Wave TypeTime (BST) & Date Wave Height & Period
Next good surf (1 star+)10AM (Thu 27th Aug)3ft (0.9m) 8s
Best Surf10AM (Thu 27th Aug)3ft (0.9m) 8s
Most Powerful 7PM (Wed 26th Aug)4.5ft (1.3m) 7s

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


The Lowdown

Alright folks, Rusty here. Let’s have a look at what Trearddur Bay (Holy Island) has in store for us over the next couple of weeks.

Straight up, it’s a tough start. The first week and a bit is pretty grim. We’ve got a long stretch of days with barely a ripple, and the wind is all over the shop. There’s a lot of cross-offshore breezes and even some glassy conditions early on the 23rd of August, but the swell is just a tiny 0.3ft from the SW. It’s basically a lake. You’d be better off finding a rock pool. That poor run carries right through until the 25th, with only a slight bump in energy on the 23rd when the wind goes glassy, but there’s still no wave to speak of.

Things start to get a bit more interesting on the 26th of August. We see a jump in swell to 2ft from the S, with a weak period of 4 seconds, but it’s a messy cross-onshore wind. The energy is still low (27). By the afternoon, it builds to 4ft from the SSW, but it’s a short-period, wind-affected mess with a strong 19 mph cross-onshore. It’s not really surfable for a paddle board.

The 27th of August morning offers a glimmer. The morning is glassy with a 3ft SSW swell and a period of 8 seconds. The combined energy is 93, which is weak, but it’s the cleanest conditions we’ve seen. It’s surfable, but ordinary. The wind swings onshore in the afternoon, so that window is tight.

The 30th of August brings a bigger bump – 5ft of SW swell with a 7-second period, and a moderate energy level of 268. But the wind is a strong cross-onshore, 16 mph, with rain showers. It’s going to be a choppy, lumpy mess. Honestly, with that setup, it looks more like a kite surfing day than a paddle surfing day.

Now, the real standout. Mark your calendars for the 2nd of September. That’s a full week away, but it’s promising. We’ve got a solid 8ft swell from the SW, with a period of 7 seconds, and a very strong combined energy of 757. The wind is offshore from the NE in the morning, swinging to a gentle offshore in the afternoon. That’s a lot of water, and it’s going to be big. For a beginner spot like this, 8ft is expert territory. The water temperature is about 63°F, which is a touch warmer than usual for this time of year.

The 3rd of September is still decent, with a 6ft swell from the WSW and a moderate offshore wind, but the energy drops to 202. It’s a step down from the day before, but still a fun option if you missed the big one.

After that, the swell fades again into the 4th and 5th of September, with smaller, cleaner but weak waves. The 5th of September is a 2ft SW swell with a light cross-offshore wind, but the energy is tiny.

So, the bottom line: the first week is a write-off. The best bet is the 2nd of September for the big, clean, expert-level swell. The 3rd of September is a solid second choice. Everything else is a mission.

Rusty.

Short Range Forecast

Light rain (total 2mm), mostly falling on Fri morning. Very mild (max 16°C on Fri morning, min 13°C on Fri night). Wind will be generally light.

Days 4-6 Weather Summary

Moderate rain (total 10mm), heaviest on Wed night. Warm (max 22°C on Tue afternoon, min 15°C on Mon night). Mainly fresh winds.

Friday
21
Saturday
22
Sunday
23
Monday
24
Tuesday
25
Wednesday
26
Thursday
27
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
1
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)
0.1
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
13
0.1
SW
14
0.1
SW
13
0.1
SW
13
0.1
SW
13
0.1
SW
13
0.4
SSE
4
0.7
S
4
1.3
SSW
6
1.1
SSW
7
0.9
SSW
8
0.7
SSW
8
0.5
SSW
7
Wave Graph
Metric surfscale
Energy kJ
7
7
7
8
8
8
8
7
7
8
7
7
7
7
7
18
98
118
93
54
30
Wind (km/h)
20
N
20
NNE
20
N
20
NNW
20
NNW
10
NNW
5
NNW
15
NNW
15
ENE
5
ENE
10
NW
20
E
25
ENE
20
ESE
15
ESE
25
SSE
30
SSE
20
SE
5
N
25
WNW
45
W
Wind State
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
glassy
cross-off
cross-off
cross-off
cross
cross-off
cross-off
cross-off
cross-off
cross-on
cross-on
cross
glassy
cross
cross-on
High Tide
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
10:57AM5.08m
11:04PM5.51m
Low Tide
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
4:43AM1.19m
4:52PM1.28m
rain showers
clear
clear
clear
clear
clear
clear
clear
clear
part cloud
part cloud
part cloud
light rain
cloud
rain showers
part cloud
light rain
thunderstorm
cloud
light rain
heavy rain
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
6:07
6:09
6:11
6:13
6:13
6:16
6:18
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
8:34
8:31
8:29
8:27
8:24
8:22
8:20
 mm
2
1
1
2
6
2
13
Temp °C
16
16
15
13
14
14
15
16
16
20
21
20
18
22
20
18
19
17
17
16
17
Feels °C
12
12
11
9
10
12
13
14
13
19
17
13
15
17
16
15
16
15
18
13
10
  • Map Icons:
  • Break
  • Live Wave Height (m)
  • Live Wind Speed (km/h)
  • Surf Rating (10 Max)
  • Ocean Swells (m)
  • Wind Speed (km/h)
Map placeholder
How to use the Wavefinder 
submit an eyeball surf report

Quick surf report for Trearddur Bay (Holy Island):

join our community of surf reporters

FREE! Surf-Forecast.com widget for your website

The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Trearddur Bay (Holy Island) surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.


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.

Nearest locationNearest