Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 29 Aug 2026:
- Most powerful swell: Saturday 5 Sep, 4AM (local time) - 7ft (2.1m), 8s period, SW swell with 481 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 2.1m 8s and forecast to arrive on Saturday (Sep 05) at 4AM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.5m 5s period and expected on Monday (Aug 31) at 7PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 4AM (Sat 5th Sep) | 7ft (2.1m) 8s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, Rusty here, and I've been staring down the charts for Trearddur Bay on Holy Island. Got to be straight with you, it's looking like a tough stretch ahead. We're kicking off the forecast period with a real quiet spell, and frankly, that's the story for most of the next two weeks.
For the first week, you're looking at a whole lot of nothing. From Saturday the 29th of August right through to the 5th of September, it's a real struggle. There's swell around, but it's all coming in short-period (mostly 6 seconds or less), and the wind is just a mess – onshore, cross-onshore, and often howling. The wave energy is weak to moderate at best. It's basically a write-off for a decent paddle.
Now, there is a bit of light on the horizon. The stand-out window, and I mean the *only* decent shot, looks to be the weekend of the 5th and 6th of September. On Saturday the 5th, the swell really starts to bump up, hitting about 6 feet (and heading toward 8 feet by the afternoon) from the SSW. The combined wave energy jumps significantly – that's a serious step up. The problem? The wind is still a problem early on Saturday. However, Sunday the 6th of September afternoon is your best bet. We've got a clean 5 foot SSW swell rolling in, and the wind goes light and cross-off from the north (N). That's the one session where Trearddur Bay might actually look like itself. But at 5 feet, it's not a beginner wave; it's bordering on a bit too much for them. Also, keep in mind this spot can get crowded and can be a fickle, inconsistent break.
After that brief glimmer of hope, we're back into the doldrums. The second week of the forecast – from the 7th of September onwards – fades away quickly. The swell drops right off, and any energy that shows up is blown out by strong winds. By the 9th of September, we're talking about ankle-biters and practically no energy out there. There is a late flash of energy on the 11th of September with a 6 foot SSW swell showing some very high energy readings, but the winds are onshore and messy, making it a non-starter. It’s a blank run, and for this area, that's not totally unusual when the weather patterns lock in.
So, bottom line? If you're keen, circle Sunday afternoon the 6th. It's the only time the numbers and conditions align. For the rest of this 16-day window, keep the board in the bag, or maybe see if the wind sets up for a kite session, because the paddle surfing outlook is grim.
Rusty.
Short Range ForecastLight rain (total 9mm), mostly falling on Sat morning. Very mild (max 17°C on Fri night, min 13°C on Mon morning). Winds increasing (light winds from the NNW on Sat afternoon, strong winds from the WNW by Sun night). | Days 4-6 Weather SummaryLight rain (total 6mm), mostly falling on Wed afternoon. Very mild (max 18°C on Tue afternoon, min 15°C on Mon night). Winds increasing (calm on Tue night, strong winds from the S by Wed afternoon). | ||||||||||||||||||||
Saturday 29 | Sunday 30 | Monday 31 | Tuesday 1 | Wednesday 2 | Thursday 3 | Friday 4 | |||||||||||||||
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) | SSW 6 | SSW 6 | SSW 9 | SW 8 | SSW 6 | SW 7 | WNW 6 | SW 8 | SW 5 | SW 6 | SSW 6 | SW 6 | SSW 6 | SSW 6 | SW 7 | WSW 5 | WSW 5 | W 5 | WSW 5 | SSW 5 | SW 8 |
Wave Graph | |||||||||||||||||||||
44 | 33 | 165 | 57 | 126 | 136 | 138 | 48 | 42 | 111 | 53 | 34 | 45 | 254 | 316 | 157 | 66 | 66 | 61 | 44 | 469 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-off | cross-on | cross-on | cross-on | cross-on | cross | on | on | on | on | glassy | cross-on | cross-on | cross-on | cross-on | on | on | on | on | cross-on |
High Tide | 11:57AM5.33m | 00:07AM5.72m | 12:28PM5.40m | 00:40AM5.74m | 1:01PM5.41m | 1:15AM5.69m | 1:36PM5.36m | 1:53AM5.56m | 2:15PM5.23m | 2:36AM5.34m | 3:01PM5.01m | 3:30AM5.02m | 3:59PM4.75m | ||||||||
Low Tide | 5:44AM0.80m | 5:55PM0.94m | 6:16AM0.70m | 6:28PM0.87m | 6:50AM0.69m | 7:04PM0.89m | 7:26AM0.78m | 7:42PM1.01m | 8:06AM0.98m | 8:25PM1.22m | 8:51AM1.28m | 9:16PM1.51m | 9:47AM1.66m | 10:23PM1.82m | |||||||
6:20 | — | — | 6:22 | — | — | 6:24 | — | — | 6:26 | — | — | 6:28 | — | — | 6:30 | — | — | 6:31 | — | — | |
— | 8:15 | — | — | 8:13 | — | — | 8:10 | — | — | 8:08 | — | — | 8:06 | — | — | 8:04 | — | — | 8:01 | — | |
mm | 3 | 1 | — | 3 | 2 | — | — | — | — | — | 1 | 1 | — | 3 | 1 | — | — | — | — | — | — |
Temp °C | 16 | 16 | 16 | 17 | 16 | 15 | 14 | 16 | 17 | 16 | 18 | 16 | 17 | 17 | 17 | 15 | 17 | 16 | 15 | 17 | 15 |
Feels °C | 15 | 14 | 14 | 13 | 10 | 11 | 9 | 12 | 13 | 11 | 15 | 16 | 12 | 11 | 11 | 7 | 11 | 10 | 8 | 11 | 7 |
Swell 1 Height (m) Direction Period (s) | SSW 6 | SSW 6 | SSW 9 | SW 8 | — | SW 7 | SW 8 | NW 5 | NNW 5 | — | WNW 4 | SW 6 | N 4 | — | SW 15 | SW 14 | SSW 7 | SW 14 | SW 14 | WNW 4 | SW 14 |
44 | 33 | 165 | 57 | — | 136 | 69 | 38 | 2 | — | 3 | 34 | 1 | — | 9 | 8 | 34 | 8 | 8 | 1 | 8 | |
Swell 2 Height (m) Direction Period (s) | — | — | NNW 3 | — | — | — | SW 8 | SW 8 | — | — | — | — | S 16 | — | — | — | SW 14 | SW 14 | — | SW 14 | — |
— | — | 1 | — | — | — | 32 | 48 | — | — | — | — | 5 | — | — | — | 8 | 8 | — | 8 | — | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | SW 14 | — |
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 8 | — | |
Wind waves Height (m) Direction Period (s) | — | NNW 2 | — | — | SSW 6 | — | WNW 6 | — | SW 5 | SW 6 | SSW 6 | — | SSW 6 | SSW 6 | SW 7 | WSW 5 | WSW 5 | W 5 | WSW 5 | SSW 5 | SW 8 |
— | 1 | — | — | 126 | — | 138 | — | 42 | 111 | 53 | — | 45 | 254 | 316 | 157 | 66 | 66 | 61 | 44 | 469 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 208 | 210 | 51 | 234 | 275 | 51 | 280 | 174 | 179 | 305 | 305 | 51 | 249 | 246 | 280 | 927 | 514 | 312 | 305 | 350 | 174 |
Best forecast wave conditions in Anglesy | |||||||||||||||||||||
Best forecast wave conditions in United Kingdom | |||||||||||||||||||||
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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.











