Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 12 Aug 2026:
- Most powerful swell: Wednesday 19 Aug, 7AM (local time) - 5.5ft (1.7m), 6s period, WNW swell with 167 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 1.7m 6s and forecast to arrive on Wednesday (Aug 19) at 7AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.7m 4s period and expected on Saturday (Aug 15) at 10AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 7AM (Wed 19th Aug) | 5.5ft (1.7m) 6s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, Rusty here again. Let’s talk Trearddur Bay on Holy Island, but in feet and miles per hour. Gotta be honest – this is a tough one. There’s a huge gap of nothing worth surfing for almost two weeks.
The first glimmer of hope is on the morning of Sunday, August 23rd. We’ve got a 5ft swell from the S, with a short period of 6 seconds, combined wave energy of 171 (moderate). The wind is light from the SE, almost glassy, so it’ll be clean. Trearddur Bay is a beginner wave, and 5ft is pushing it for a novice, but for a surfer who’s been waiting, it’s the best looking window.
That same afternoon, the swell builds to 6ft from the SSW, with a period of 7 seconds and combined energy of 322 (moderate to strong). That’s the most power on offer, but the wind swings onshore from the SW at 9 mph, chopping it up. The direction is fine for the break, but the wind is a buzzkill.
The pick of the whole outlook is the morning of the 23rd of August – cleanest conditions, but not a huge swell. The afternoon of the 23rd of August has more grunt but worse wind. There’s just no perfect day here.
Water temp is about 63°F, a touch warmer than average for this time of year.
So, hang tight, keep an eye on things, and if you’re desperate, aim for the 23rd of August morning. If not, it’s a good time to clean the wax off.
Rusty.
Short Range ForecastSome drizzle, heaviest during Fri morning. Warm (max 26°C on Wed afternoon, min 14°C on Sat morning). Wind will be generally light. | Days 5-7 Weather SummarySome drizzle, heaviest during Sun morning. Very mild (max 17°C on Mon night, min 13°C on Sun morning). Wind will be generally light. | |||||||||||||||||||
Wed 12 | Thursday 13 | Friday 14 | Saturday 15 | Sunday 16 | Monday 17 | Tuesday 18 | ||||||||||||||
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) | SW 12 | SW 11 | SW 11 | SW 11 | SW 5 | SW 4 | NW 4 | SW 6 | SW 6 | SW 6 | SW 6 | N 4 | W 7 | W 7 | S 3 | SSW 5 | SSW 4 | SW 4 | SW 5 | WSW 5 |
Wave Graph  | ||||||||||||||||||||
 kJ | 6 | 5 | 5 | 4 | 25 | 7 | 5 | 1 | 1 | 2 | 1 | 0 | 1 | 1 | 5 | 61 | 12 | 10 | 94 | 76 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross-on | on | on | cross-on | cross | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-on | cross-off | cross-on | on | cross-on | cross-on | cross-on | cross |
High Tide | 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 | 2:12PM5.16m | 2:28AM5.33m | 2:51PM4.93m | 3:07AM4.98m | |||||||
Low Tide | 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 | 8:05AM0.82m | 8:13PM1.14m | 8:44AM1.19m | 8:54PM1.47m | |||||||
 |  |  | |  |  | |  | | | | | | | |  | | |  | | |
 | — | — | 5:54 | — | — | 5:54 | — | — | 5:56 | — | — | 5:58 | — | — | 6:01 | — | — | 6:01 | — | — |
 | 8:52 | — | — | 8:51 | — | — | 8:49 | — | — | 8:46 | — | — | 8:45 | — | — | 8:43 | — | — | 8:40 | — |
mm | — | — | — | — | — | 1 | — | — | — | — | — | 1 | — | — | — | — | — | — | 1 | — |
Temp °C | 26 | 25 | 21 | 22 | 19 | 16 | 17 | 17 | 14 | 16 | 15 | 13 | 13 | 13 | 14 | 16 | 17 | 16 | 17 | 16 |
Feels °C | 24 | 23 | 20 | 22 | 17 | 15 | 15 | 13 | 10 | 13 | 12 | 12 | 12 | 12 | 11 | 13 | 16 | 14 | 10 | 9 |
Swell 1 Height (m) Direction Period (s) | SSW 3 | SW 10 | SW 8 | SW 8 | S 11 | SW 4 | NW 4 | SW 6 | SW 6 | SW 6 | SW 6 | — | W 7 | N 4 | — | — | SSW 4 | — | S 16 | — |
| kJ | 2 | 4 | 3 | 2 | 2 | 7 | 3 | 1 | 1 | 2 | 1 | — | 1 | 1 | — | — | 12 | — | 5 | — |
Swell 2 Height (m) Direction Period (s) | SW 12 | — | SW 5 | SW 11 | — | — | SW 4 | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | 6 | — | 1 | 4 | — | — | 3 | — | — | — | — | — | — | — | — | — | — | — | — | — |
Swell 3 Height (m) Direction Period (s) | SW 6 | SW 11 | SW 11 | S 11 | — | — | N 4 | — | — | — | — | — | — | W 7 | — | — | — | — | — | — |
| kJ | 1 | 5 | 5 | 2 | — | — | 3 | — | — | — | — | — | — | 1 | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | — | SSW 5 | SSW 3 | SSW 2 | SW 5 | NW 3 | NW 4 | N 4 | NNW 4 | NNW 4 | N 3 | N 4 | NNW 4 | — | S 3 | SSW 5 | W 2 | SW 4 | SW 5 | WSW 5 |
| kJ | — | 3 | 1 | 1 | 25 | 3 | 5 | 5 | 18 | 9 | 3 | 9 | 6 | — | 5 | 61 | 1 | 10 | 94 | 76 |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 161 | 155 | 179 | 249 | 179 | 192 | 368 | 323 | 323 | 589 | 251 | 246 | 246 | 285 | 275 | 288 | 280 | 192 | 252 | 219 |
Best forecast wave conditions in Anglesy | ||||||||||||||||||||
Best forecast wave conditions in United Kingdom | ||||||||||||||||||||
Header Global | ||||||||||||||||||||
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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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