Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 5 Aug 2026:
- Most powerful swell: Wednesday 5 Aug, 1PM (local time) - 5ft (1.6m), 6s period, W swell with 163 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 1.6m 6s and forecast to arrive on Wednesday (Aug 05) at 1PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.1m 5s period and expected on Thursday (Aug 06) at 10AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 1PM (Wed 5th Aug) | 5ft (1.6m) 6s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s have a look at what Trearddur Bay has in store for us over the next couple of weeks.
Well, I’ll be honest with you, the outlook is a tough one. For the first twelve days, from the 5th of August through to the 16th of August, it’s pretty much a write-off. The wave energy is mostly weak, often under 30 (as low as 1 on the 11th), and the swell is tiny and short-period. You’re looking at a lot of cross-onshore winds and lumpy, choppy conditions. Even when the wind swings offshore on the 11th, the swell is barely a ripple at 1ft. It’s a long, dry spell for paddle surfing.
The water temperature on the 5th of August is sitting at 62°, which is a touch warmer than normal for the time of year, so at least a wetsuit isn’t a total battle.
Now, the real story is what happens on the 17th of August. The swell finally wakes up. Monday morning delivers a 4ft swell from the southwest with a short period of 8 seconds and a moderate wave energy of 408, but it’s a cross-shore wind making it lumpy. The stand-out, however, is Monday afternoon. The swell jumps to 8ft from the northwest, with a period of 7 seconds and a strong wave energy of 622. The wind is onshore from the southwest, so it’s going to be a messy, powerful beast. At 8ft, this is strictly for experts only. The combined energy really shows the power (622). This is the only real highlight in the whole forecast, and being over a week away, it’s promising but not locked in.
The following days, the 18th and 19th, clean up a bit with cross-offshore winds, but the swell drops back down to 2ft to 2ft with moderate energy.
So, for the keen crew, that Monday afternoon, 17th of August, is the one day to circle on the calendar. It’s the only shot of real size, even if the wind won’t be perfect. For the rest of the window, it’s flat and messy. You’d be better off cleaning the wax off your board.
Stay hopeful, Rusty.
Short Range ForecastLight rain (total 3mm), mostly falling on Wed afternoon. Very mild (max 16°C on Wed afternoon, min 13°C on Wed night). Winds decreasing (fresh winds from the W on Wed morning, light winds from the W by Fri morning). | Days 4-6 Weather SummarySome drizzle, heaviest during Sun morning. Very mild (max 18°C on Sun afternoon, min 13°C on Mon night). Winds decreasing (fresh winds from the SSW on Sat morning, light winds from the WSW by Sun night). | ||||||||||||||||||||
Wednesday 5 | Thursday 6 | Friday 7 | Saturday 8 | Sunday 9 | Monday 10 | Tuesday 11 | |||||||||||||||
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 5 | SW 6 | NW 5 | SW 6 | WSW 4 | SW 4 | SW 4 | SW 5 | SW 5 | SSW 4 | SSW 4 | SW 5 | WSW 4 | NW 4 | WNW 4 | W 4 | SW 6 | SW 4 | SW 4 | SW 6 | SW 6 |
Wave Graph  | |||||||||||||||||||||
 kJ | 117 | 66 | 74 | 9 | 8 | 7 | 6 | 6 | 22 | 16 | 35 | 47 | 17 | 8 | 28 | 28 | 11 | 8 | 3 | 1 | 1 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | cross | cross | on | cross-on | cross-on | on | cross-on | cross-on | cross-on | cross-on | on | on | on | cross-off | cross-off | off | off | cross-off | cross-off |
High Tide | 3:31PM4.87m | 3:52AM5.04m | 4:26PM4.70m | 4:55AM4.80m | 5:37PM4.56m | 6:16AM4.64m | 7:05PM4.57m | 7:47AM4.68m | 8:27PM4.80m | 9:03AM4.91m | 9:30PM5.16m | 10:01AM5.19m | 10:21PM5.51m | ||||||||
Low Tide | 9:40PM1.55m | 10:13AM1.46m | 10:41PM1.77m | 11:18AM1.72m | 11:58PM1.91m | 12:38PM1.85m | 1:25AM1.83m | 1:59PM1.77m | 2:41AM1.51m | 3:06PM1.52m | 3:41AM1.10m | 4:01PM1.21m | |||||||||
 |  |  |  | |  | | | | | | | | |  | | |  | | | | |
 | 5:39 | — | — | 5:41 | — | — | 5:43 | — | — | 5:45 | — | — | 5:47 | — | — | 5:48 | — | — | 5:50 | — | — |
 | — | — | 9:07 | — | — | 9:05 | — | — | 9:02 | — | — | 9:00 | — | 8:59 | — | — | 8:57 | — | — | 8:54 | — |
mm | — | 2 | 1 | — | — | — | — | — | — | — | — | — | 1 | — | — | — | — | — | — | — | — |
Temp °C | 15 | 16 | 15 | 14 | 15 | 16 | 15 | 16 | 16 | 16 | 17 | 17 | 17 | 18 | 17 | 15 | 16 | 15 | 16 | 17 | 18 |
Feels °C | 8 | 11 | 9 | 10 | 12 | 12 | 14 | 12 | 12 | 10 | 12 | 14 | 16 | 16 | 14 | 12 | 13 | 12 | 13 | 13 | 16 |
Swell 1 Height (m) Direction Period (s) | — | SW 6 | SW 6 | SW 6 | N 5 | SW 4 | SW 4 | WNW 3 | SW 12 | SW 11 | S 11 | S 11 | SW 7 | NW 4 | SW 6 | — | NW 4 | S 11 | S 11 | — | SW 6 |
| kJ | — | 66 | 19 | 9 | 12 | 7 | 5 | 1 | 5 | 5 | 2 | 2 | 7 | 8 | 2 | — | 3 | 2 | 2 | — | 1 |
Swell 2 Height (m) Direction Period (s) | — | S 13 | SW 13 | S 13 | S 12 | N 4 | NW 3 | S 12 | W 12 | — | — | — | S 12 | SW 6 | S 12 | — | NNW 4 | — | S 11 | SW 6 | — |
| kJ | — | 3 | 7 | 3 | 3 | 1 | 3 | 3 | 3 | — | — | — | 3 | 5 | 3 | — | 2 | — | 2 | 1 | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | SW 12 | SW 12 | SW 12 | — | — | — | — | — | — | SW 12 | — | — | — | — | — | — | — |
| kJ | — | — | — | — | 6 | 6 | 6 | — | — | — | — | — | — | 6 | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | W 5 | WNW 5 | NW 5 | NW 5 | WSW 4 | — | — | SW 5 | SW 5 | SSW 4 | SSW 4 | SW 5 | WSW 4 | SW 4 | WNW 4 | W 4 | SW 6 | SW 4 | SW 4 | — | ENE 3 |
| kJ | 117 | 56 | 74 | 62 | 8 | — | — | 6 | 22 | 16 | 35 | 47 | 17 | 5 | 28 | 28 | 11 | 8 | 3 | — | 1 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 462 | 459 | 323 | 195 | 325 | 283 | 280 | 251 | 246 | 246 | 323 | 182 | 246 | 246 | 192 | 410 | 368 | 275 | 285 | 285 | 284 |
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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