
Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 27 Jul 2026:
- Most powerful swell: Thursday 30 Jul, 10PM (local time) - 4.5ft (1.4m), 6s period, SW swell with 118 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 1.4m 6s and forecast to arrive on Thursday (Jul 30) at 10PM. 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 4s period and expected on Monday (Aug 03) at 7AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 10PM (Thu 30th Jul) | 4.5ft (1.4m) 6s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, Rusty here again, giving you the same outlook but in feet and miles per hour for our imperial crew. So for Trearddur Bay (Holy Island), it’s a tough forecast. The first 10 days or so? Dead. Nothing worth paddling for. Tiny swell, bad winds, and combined wave energy readings that are basically a whisper – values like 24, 46, and 80 are all in the weak category. You’ve got a big gap with no recommendations for days.
The first real glimmer of hope comes on Friday, 7th of August. That morning, the swell bumps up to about 5ft from the SW, with a short 6-second period – it’s windswell, not groundswell. The combined energy hits 192, which is a nice moderate level. The key is the wind: a light 10 mph breeze from the NNW, blowing clean offshore, keeping the surface glassy. That’s your best bet. The afternoon holds similar size at around 5ft with 226 energy and still clean, but the rating is still poor.
After that, it fades. The rest of the second week shows some 4-5ft days but with messy cross-shore winds and chop. Nothing world-beating.
Moral of the story: if you want a wave, be at Trearddur Bay on the morning of the 7th of August. It’s not perfect, but it’s the only game in town for a while.
Rusty.
Short Range ForecastMostly dry. Very mild (max 19°C on Mon night, min 14°C on Sun night). Mainly fresh winds. | Days 4-6 Weather SummarySome drizzle, heaviest during Wed night. Very mild (max 17°C on Wed night, min 13°C on Thu night). Wind will be generally light. | ||||||||||||||||||||
Monday 27 | Tuesday 28 | Wednesday 29 | Thursday 30 | Friday 31 | Saturday 1 | Sunday 2 | |||||||||||||||
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) | W 4 | SW 4 | SW 5 | SSW 5 | SSW 5 | SW 5 | SSW 4 | SSW 4 | SW 5 | WSW 5 | SSW 4 | SW 6 | SW 6 | SW 6 | SW 4 | SW 5 | W 3 | SW 4 | W 9 | W 8 | SW 8 |
Wave Graph | |||||||||||||||||||||
24 | 25 | 22 | 46 | 80 | 49 | 10 | 7 | 66 | 51 | 32 | 80 | 17 | 5 | 5 | 7 | 1 | 1 | 2 | 1 | 3 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | on | cross-on | on | cross-on | cross-on | cross-on | cross-on | cross-on | cross | on | cross-off | cross | on | cross-on | cross-on | on | cross-on | glassy | cross | glassy |
High Tide | 10:10AM4.66m | 10:22PM5.05m | 10:47AM4.83m | 10:57PM5.25m | 11:21AM4.96m | 11:31PM5.40m | 11:54AM5.05m | 00:03AM5.49m | 12:26PM5.10m | 00:36AM5.52m | 12:58PM5.13m | 1:09AM5.52m | 1:32PM5.12m | 1:43AM5.48m | |||||||
Low Tide | 4:07PM1.71m | 4:33AM1.50m | 4:44PM1.52m | 5:08AM1.29m | 5:17PM1.36m | 5:41AM1.11m | 5:50PM1.23m | 6:14AM0.99m | 6:23PM1.15m | 6:46AM0.92m | 6:56PM1.12m | 7:20AM0.89m | 7:31PM1.14m | ||||||||
5:26 | — | — | 5:26 | — | — | 5:28 | — | — | 5:30 | — | — | 5:31 | — | — | 5:33 | — | — | 5:35 | — | — | |
— | — | 9:22 | — | — | 9:21 | — | — | 9:19 | — | — | 9:17 | — | — | 9:15 | — | — | 9:14 | — | — | 9:12 | |
mm | — | — | — | — | — | — | — | — | 1 | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 15 | 18 | 19 | 18 | 18 | 17 | 17 | 18 | 17 | 15 | 16 | 16 | 13 | 14 | 16 | 13 | 16 | 16 | 17 | 18 | 19 |
Feels °C | 11 | 15 | 18 | 13 | 13 | 13 | 14 | 15 | 14 | 12 | 12 | 15 | 9 | 12 | 14 | 10 | 13 | 12 | 15 | 16 | 16 |
Swell 1 Height (m) Direction Period (s) | NNW 5 | N 4 | WNW 3 | — | — | — | — | — | — | — | NW 4 | SW 6 | SW 6 | SW 6 | — | SW 5 | SW 5 | SW 4 | — | W 8 | SW 8 |
5 | 2 | 1 | — | — | — | — | — | — | — | 4 | 80 | 16 | 5 | — | 7 | 1 | 1 | — | 1 | 3 | |
Swell 2 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | N 4 | — | — | — | — | W 9 | — | — |
— | — | — | — | — | — | — | — | — | — | — | — | — | 1 | — | — | — | — | 2 | — | — | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | N 4 | — | — | — | — | — | — | — |
— | — | — | — | — | — | — | — | — | — | — | — | — | 1 | — | — | — | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | W 4 | SW 4 | SW 5 | SSW 5 | SSW 5 | SW 5 | SSW 4 | SSW 4 | SW 5 | WSW 5 | SSW 4 | — | NW 4 | WNW 4 | SW 4 | NW 3 | W 3 | — | — | NNE 2 | N 3 |
24 | 25 | 22 | 46 | 80 | 49 | 10 | 7 | 66 | 51 | 32 | — | 17 | 4 | 5 | 2 | 1 | — | — | 1 | 5 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 251 | 236 | 246 | 251 | 246 | 246 | 255 | 306 | 88 | 252 | 586 | 8 | 192 | 517 | 289 | 293 | 928 | 246 | 249 | 287 | 253 |
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)
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.










