Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 10 Aug 2026:
- Most powerful swell: Friday 14 Aug, 1AM (local time) - 2.5ft (0.8m), 5s period, SW swell with 31 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 0.8m 5s and forecast to arrive on Friday (Aug 14) at 1AM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.7m 5s period and expected on Sunday (Aug 16) at 4AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 1AM (Fri 14th Aug) | 2.5ft (0.8m) 5s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, listen up, crew. Let’s talk about what’s coming for Trearddur Bay (Holy Island). Gotta be straight with you: the next week-plus is a total flat spell. Nothing doing until things finally fire up around the 19th.
From Monday the 10th right through to Monday the 17th? Brutal. Tiny, weak, messy. Swell heights are barely a bump – 1ft at best with a weak 9 combined energy, and a short period of 6 seconds. The wind is mostly cross-off or onshore, but there’s just no wave energy. It’s flat, boys. Don’t even bother with the wetsuit. Check the tide pools instead.
There’s a tiny glimmer on Tuesday the 18th. The morning is glassy, with 3ft of swell from the SSW. That’s a tiny wave, 4-second period – barely a bump, but that glassy wind is a beautiful thing. No rideable waves there, though.
Wednesday the 19th afternoon is where we finally get a pulse. We jump to 5ft of swell from the SW (optimum direction), with a 6-second period and 133 combined energy – that’s moderate punch. The wind turns offshore from the NE at 15 mph. It’s clean, it’s gentle, and for Trearddur Bay, this is our first real chance. The waves are surfable, but conditions are still a bit ordinary. It’s not a standout, but it’s the first light in the tunnel.
Now, the real standout lands on Monday the 24th. The morning starts with 5ft from the S, a 5-second period and 153 energy – moderate. That’s okay. But the afternoon… that’s the one. The swell jumps to 7ft from the S, 6-second period, and 389 combined energy – that’s strong stuff. The wind is offshore from the NNE at 12 mph, keeping things clean. This is “expect good surf conditions” territory. That’s a legit, fun-sized wave for Trearddur. 7ft is pushing it for the beginners, but for anyone with some experience, that’s an afternoon session to circle on the calendar. It’s the best on offer by a country mile.
After that, Tuesday the 25th morning drops back to 3ft from the SSW, with 76 energy and a cross-off wind. A definite drop-off.
So, the word from Rusty: the shop is closed until the 19th, and the real treasure is waiting for you on the afternoon of the 24th. That’s the one to go for.
Rusty, signing off.
Short Range ForecastMostly dry. Warm (max 24°C on Wed afternoon, min 14°C on Mon morning). Wind will be generally light. | Days 4-6 Weather SummarySome drizzle, heaviest during Thu night. Warm (max 23°C on Thu morning, min 14°C on Fri night). Wind will be generally light. | ||||||||||||||||||||
Monday 10 | Tuesday 11 | Wednesday 12 | Thursday 13 | Friday 14 | Saturday 15 | Sunday 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) | SW 6 | SW 6 | SSW 6 | SSW 6 | S 3 | S 11 | SW 12 | SW 12 | SW 10 | SW 10 | SW 11 | SW 5 | NW 4 | SW 6 | NW 3 | NW 4 | WNW 4 | SW 6 | N 5 | N 4 | — |
Wave Graph  | |||||||||||||||||||||
 kJ | 8 | 5 | 4 | 4 | 1 | 2 | 5 | 6 | 4 | 4 | 5 | 31 | 18 | 8 | 6 | 17 | 2 | 1 | 0 | 0 | 0 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-off | cross-off | cross-on | on | cross | cross-on | cross-on | cross | on | cross-on | on | cross | cross | cross-off | cross | cross-off | off | glassy | on | cross-on |
High Tide | 9:30PM5.16m | 10:01AM5.19m | 10:21PM5.51m | 10:50AM5.42m | 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 | ||||||||
Low Tide | 3:06PM1.52m | 3:41AM1.10m | 4:01PM1.21m | 4:33AM0.72m | 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 | ||||||||
 | |  |  | | | | | | | |  | | | | | | | | | | |
 | 5:48 | — | — | 5:50 | — | — | 5:52 | — | — | 5:54 | — | — | 5:54 | — | — | 5:56 | — | — | 5:58 | — | — |
 | — | 8:57 | — | — | 8:54 | — | — | 8:52 | — | — | 8:51 | — | — | 8:49 | — | — | 8:46 | — | — | 8:45 | — |
mm | — | — | — | — | — | — | — | — | — | — | — | 1 | — | — | — | — | — | — | — | — | — |
Temp °C | 14 | 16 | 17 | 20 | 21 | 21 | 22 | 24 | 24 | 23 | 23 | 20 | 15 | 18 | 18 | 16 | 16 | 16 | 14 | 16 | 16 |
Feels °C | 11 | 13 | 14 | 17 | 18 | 20 | 19 | 21 | 21 | 22 | 23 | 19 | 13 | 16 | 15 | 12 | 13 | 14 | 13 | 14 | 13 |
Swell 1 Height (m) Direction Period (s) | SW 6 | SW 6 | SSW 6 | SSW 6 | SW 6 | SSW 3 | SW 12 | SSW 3 | SW 5 | SW 8 | SW 8 | SW 5 | SW 5 | WNW 4 | SSW 6 | SW 5 | WNW 4 | SW 6 | — | N 4 | — |
| kJ | 8 | 5 | 4 | 4 | 1 | 1 | 5 | 1 | 1 | 3 | 2 | 31 | 9 | 2 | 3 | 1 | 2 | 1 | — | 3 | — |
Swell 2 Height (m) Direction Period (s) | S 10 | — | — | — | — | SW 6 | SW 6 | SW 12 | SW 10 | SW 5 | SW 11 | — | — | SW 6 | SW 8 | SW 7 | N 4 | — | — | — | — |
| kJ | 2 | — | — | — | — | 1 | 1 | 6 | 4 | 1 | 5 | — | — | 8 | 2 | 2 | 3 | — | — | — | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | S 11 | W 10 | SW 6 | — | SW 10 | S 11 | — | — | N 4 | — | — | SW 5 | — | — | — | — |
| kJ | — | — | — | — | — | 2 | 2 | 1 | — | 4 | 2 | — | — | 1 | — | — | 1 | — | — | — | — |
Wind waves Height (m) Direction Period (s) | N 4 | N 4 | — | — | S 3 | — | SSW 3 | — | — | — | — | WNW 3 | NW 4 | — | NW 3 | NW 4 | NW 4 | N 4 | N 5 | — | — |
| kJ | 8 | 3 | — | — | 1 | — | 3 | — | — | — | — | 4 | 18 | — | 6 | 17 | 7 | 12 | 16 | — | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 251 | 275 | 246 | 284 | 304 | 163 | 161 | 178 | 163 | 187 | 249 | 51 | 179 | 326 | 163 | 195 | 589 | 194 | 246 | 246 | 273 |
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.
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