Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 10 Sep 2026:
- Most powerful swell: Thursday 10 Sep, 4PM (local time) - 7ft (2.2m), 7s period, SSW swell with 437 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 2.2m 7s and forecast to arrive on Thursday (Sep 10) at 4PM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.5m 6s period and expected on Wednesday (Sep 16) at 4AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 4PM (Thu 10th Sep) | 7ft (2.2m) 7s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, let’s talk about Trearddur Bay on Holy Island. It’s been a tough stretch, and honestly, I’m looking at a forecast that’s just not giving us much to work with for the next 16 days. The only flicker of hope is a long way off, so keep your expectations in check.
Right now, from Thursday the 10th through to the 24th, it’s pretty much a write-off. We’ve got swells coming and going, but the wind is a mess – strong cross-onshore or onshore winds, with a few days of 25 mph gusts. The water temp is a touch warmer than normal at 62°, which is nice, but it doesn’t help the surf. Thursday morning has a 6 ft SSW swell, but with that 28 mph S wind, it’s just a blown-out, messy cross-onshore situation. The combined energy is moderate at 173, but it’s all junk. The swell period is a short 6 seconds, so no real power. Later that afternoon, we get a 7 ft SSW swell with 25 mph winds – that’s too big for beginners and onshore, so it’s only for the keenest if at all.
Friday and Saturday are similar. Friday morning drops to 2 ft, Sunday morning has a little 2 ft bump with a light NNE offshore breeze, which actually cleans things up, but the swell is tiny with only 26 of combined energy. That’s weak. The period is 6 seconds, so no push. Sunday afternoon is even smaller. The whole first week is a dud for real surfing.
The second week stays quiet. There’s a bit of a spike on Monday the 23rd with a 3 ft SSW swell, but it’s onshore, and on Wednesday the 24th, we get a 6 ft SW swell with 22 mph winds – still onshore. The period is only 6 seconds, so it’s messy again.
Finally, we get a standout on Friday the 25th of September. The morning shows a 7 ft WSW swell with a 6-second period, and a light 6 mph E wind blowing cross-offshore. That’s clean. The combined energy is moderate at 382. But here’s the catch: Trearddur Bay is inconsistent, and it rarely breaks well. With a long period of 6 seconds? No, it’s short-period, so it’s not going to have that long, clean shape. Still, if the wind holds, that Friday morning might be your one shot. It’s a beginner-friendly break, but at 7 ft, it’s getting a bit big for absolute beginners. The tide and sandbanks will be key. The crowds are sometimes an issue here, so if you’re out for that Friday window, expect company.
For the rest of the 16 days, there’s barely a ripple. The 20th and 21st have a tiny 0.3 ft S swell with a very long 14-second period, but the wind is strong cross-onshore, so it’s just chop. Honestly, the best advice I can give is to keep an eye on the long-range forecasts – things can change, but right now, it’s a waiting game.
Rusty
Short Range ForecastLight rain (total 5mm), mostly falling on Thu afternoon. Very mild (max 18°C on Thu night, min 13°C on Fri morning). Winds decreasing (near gales from the SSW on Thu morning, light winds from the W by Sat night). | Days 4-6 Weather SummaryLight rain (total 2mm), mostly falling on Mon night. Very mild (max 18°C on Mon afternoon, min 13°C on Tue night). Winds increasing (calm on Sun afternoon, strong winds from the SSW by Mon night). | ||||||||||||||||||||
Thursday 10 | Friday 11 | Saturday 12 | Sunday 13 | Monday 14 | Tuesday 15 | Wednesday 16 | |||||||||||||||
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 7 | SW 7 | SW 7 | SW 6 | SW 5 | SW 7 | SW 7 | SW 6 | SSW 6 | SW 6 | SSW 6 | SSW 4 | SSW 5 | SSW 6 | SW 6 | WNW 4 | SW 6 | SSW 7 | SW 6 | SW 6 |
Wave Graph  | |||||||||||||||||||||
 kJ | 173 | 437 | 106 | 44 | 20 | 67 | 363 | 332 | 97 | 26 | 9 | 13 | 31 | 77 | 184 | 68 | 25 | 5 | 5 | 2 | 1 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | on | cross-on | cross | cross-on | cross-on | on | on | cross-on | off | cross-off | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-off | cross-off | cross-off | cross |
High Tide | 10:36AM5.47m | 10:49PM5.85m | 11:14AM5.59m | 11:28PM5.95m | 11:50AM5.61m | 00:04AM5.91m | 12:25PM5.56m | 00:40AM5.77m | 1:00PM5.44m | 1:15AM5.55m | 1:34PM5.27m | 1:50AM5.26m | 2:09PM5.06m | 2:27AM4.94m | |||||||
Low Tide | 4:32PM0.95m | 5:00AM0.47m | 5:11PM0.75m | 5:39AM0.42m | 5:49PM0.68m | 6:16AM0.50m | 6:26PM0.74m | 6:52AM0.70m | 7:02PM0.91m | 7:27AM0.99m | 7:38PM1.17m | 8:03AM1.34m | 8:16PM1.50m | ||||||||
 |  |  |  | |  | |  | | | | | | | |  | | | | | | |
 | 6:41 | — | — | 6:43 | — | — | 6:45 | — | — | 6:47 | — | — | 6:48 | — | — | 6:50 | — | — | 6:52 | — | — |
 | — | 7:46 | — | — | 7:45 | — | — | 7:42 | — | — | 7:39 | — | — | 7:37 | — | — | 7:35 | — | — | 7:32 | — |
mm | — | 2 | — | — | — | 1 | — | 1 | 1 | — | — | — | — | — | 1 | — | 1 | — | — | — | — |
Temp °C | 16 | 17 | 18 | 14 | 14 | 16 | 17 | 17 | 18 | 15 | 15 | 16 | 17 | 18 | 17 | 16 | 16 | 15 | 13 | 14 | 14 |
Feels °C | 7 | 13 | 15 | 10 | 11 | 9 | 12 | 14 | 18 | 13 | 14 | 13 | 13 | 13 | 12 | 12 | 14 | 12 | 7 | 10 | 12 |
Swell 1 Height (m) Direction Period (s) | — | — | SW 7 | SW 7 | SW 6 | — | — | — | SW 6 | SSW 6 | NNW 5 | N 4 | — | SW 12 | — | SW 6 | SW 6 | SW 6 | SSW 7 | SW 6 | SW 6 |
| kJ | — | — | 106 | 44 | 20 | — | — | — | 97 | 26 | 7 | 1 | — | 6 | — | 68 | 16 | 5 | 5 | 2 | 1 |
Swell 2 Height (m) Direction Period (s) | — | — | — | — | N 4 | — | — | — | — | — | SW 6 | — | — | — | — | — | — | S 11 | SW 11 | — | SW 6 |
| kJ | — | — | — | — | 3 | — | — | — | — | — | 9 | — | — | — | — | — | — | 2 | 5 | — | 1 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | WNW 3 | — | — | — | — | — | — | — | — | S 6 | — |
| kJ | — | — | — | — | — | — | — | — | — | — | 1 | — | — | — | — | — | — | — | — | 1 | — |
Wind waves Height (m) Direction Period (s) | SSW 6 | SSW 7 | W 4 | NW 4 | WNW 4 | SW 5 | SW 7 | SW 7 | WNW 4 | NNW 5 | — | SSW 6 | SSW 4 | SSW 5 | SSW 6 | WNW 4 | WNW 4 | NW 5 | NNW 6 | NNW 5 | NNW 5 |
| kJ | 173 | 437 | 7 | 17 | 6 | 67 | 363 | 332 | 15 | 19 | — | 13 | 31 | 77 | 184 | 19 | 25 | 56 | 119 | 78 | 45 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 292 | 480 | 255 | 179 | 51 | 299 | 319 | 88 | 88 | 51 | 179 | 246 | 186 | 251 | 206 | 51 | 1142 | 179 | 226 | 192 | 192 |
Best forecast wave conditions in Anglesy | |||||||||||||||||||||
Best forecast wave conditions in United Kingdom | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
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