
Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 4 Aug 2026:
- Most powerful swell: Saturday 8 Aug, 4PM (local time) - 5.5ft (1.7m), 6s period, SW swell with 189 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 Saturday (Aug 08) at 4PM. 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 1PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 4PM (Sat 8th Aug) | 5.5ft (1.7m) 6s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, I’ll be straight with you – don’t get your hopes up. The next 16 days look pretty grim for Trearddur Bay (Holy Island). The forecast is basically a long stretch of weak, short-period windswell getting hammered by onshore or cross-onshore winds. There’s not a single morning or afternoon that scores more than a zero for surf quality, so I can’t honestly point you to one standout window. You’re looking at a solid run of poor conditions from the start on Tuesday, August 4th, all the way through to Wednesday, August 19th.
The first couple of days, Tuesday August 4th and Wednesday August 5th, are a write-off. We’ve got a 4ft to 5ft swell, but it’s coming from the SSW and W with a pitiful 5 to 6-second period, so it’s all chop and no shape. The wind is blowing 15 to 25 mph from the SSE and W, making it cross-onshore and messy. The combined wave energy is weak, around 70 to 152 (moderate at best), but it’s just not surfable. The water temp is about average for the time of year, but that’s the only thing that’s decent.
Thursday August 6th morning sees a 5ft NW swell, period still only 6 seconds, and it’s a cross-shore wind from the WNW at 15 mph, so there’s a cross-chop on it. The afternoon drops off to a tiny 1ft with light offshore wind, but it’s just too small. Friday August 7th onward is a slow bleed of tiny waves – 2ft, 3ft, 4ft – all with short period and onshore or cross-onshore breezes. The wind does go light and glassy for a moment on Tuesday August 11th morning, but the swell is a pathetic 0.7ft, so you’d be bobbing on a lake.
The second week doesn’t get any better. From August 12th to 19th, the swell height rarely cracks 3ft, and when it does, like on Saturday August 15th and Tuesday August 18th, the period is still short (5 to 6 seconds) and the wind is onshore or strong cross-onshore, blowing 19 to 31 mph. The combined energy on Tuesday August 18th morning hits 196 (moderate), but with a 6ft swell and period of 6 seconds, plus a near gale from the SW, that’s just a washing machine. Trearddur Bay is a fairly exposed beginner spot that’s inconsistent at the best of times, and this forecast is a total blank. For a place like this, a long dry spell isn’t unusual, but it still stings.
Honestly, with that much wind and that poor wave quality, it looks more interesting for kite surfing than paddle surfing. Sorry, folks. Keep an eye on the charts – it tends not to stay this poor forever.
Rusty
Short Range ForecastLight rain (total 7mm), mostly falling on Mon night. Very mild (max 18°C on Mon night, min 13°C on Wed night). Winds increasing (light winds from the SSE on Mon night, strong winds from the W by Wed morning). | Days 4-6 Weather SummaryMostly dry. Very mild (max 19°C on Sun afternoon, min 14°C on Thu night). Winds decreasing (fresh winds from the SSW on Sat afternoon, light winds from the W by Sun afternoon). | ||||||||||||||||||||
Tuesday 4 | Wednesday 5 | Thursday 6 | Friday 7 | Saturday 8 | Sunday 9 | Monday 10 | |||||||||||||||
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 5 | SSW 5 | SW 6 | W 6 | W 5 | WNW 6 | NW 6 | SW 6 | SW 5 | W 4 | SW 4 | SW 5 | SW 4 | SW 6 | SW 6 | SW 6 | SW 6 | SW 7 | NW 4 | S 12 | SW 6 |
Wave Graph | |||||||||||||||||||||
70 | 74 | 75 | 152 | 92 | 173 | 124 | 11 | 10 | 10 | 22 | 42 | 43 | 189 | 80 | 15 | 10 | 7 | 14 | 3 | 1 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | cross | on | on | on | cross-on | on | cross-on | cross-on | cross-on | on | cross-on | off | cross-off | cross-off | off |
High Tide | 2:46PM5.01m | 3:02AM5.25m | 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 | ||||||||
Low Tide | 8:35AM1.03m | 8:51PM1.35m | 9:20AM1.21m | 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 | |||||||
5:37 | — | — | 5:39 | — | — | 5:41 | — | — | 5:43 | — | — | 5:45 | — | — | 5:47 | — | — | 5:48 | — | — | |
— | — | 9:08 | — | — | 9:07 | — | — | 9:05 | — | — | 9:02 | — | — | 9:00 | — | 8:59 | — | — | 8:57 | — | |
mm | — | — | 1 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 18 | 18 | 17 | 15 | 17 | 15 | 14 | 15 | 16 | 15 | 16 | 16 | 16 | 17 | 16 | 16 | 19 | 18 | 16 | 17 | 16 |
Feels °C | 15 | 14 | 12 | 8 | 11 | 7 | 10 | 12 | 12 | 11 | 11 | 12 | 11 | 11 | 13 | 16 | 18 | 18 | 13 | 13 | 13 |
Swell 1 Height (m) Direction Period (s) | NE 4 | — | SW 6 | — | S 13 | S 13 | SW 6 | NW 5 | N 4 | SW 12 | NW 4 | SW 12 | SW 11 | — | S 11 | SW 6 | NW 4 | SW 7 | SSW 5 | NNW 4 | SW 6 |
1 | — | 75 | — | 3 | 3 | 18 | 25 | 1 | 6 | 1 | 5 | 5 | — | 2 | 15 | 3 | 7 | 2 | 3 | 1 | |
Swell 2 Height (m) Direction Period (s) | — | — | SSW 7 | — | — | — | S 13 | S 12 | SW 12 | — | SW 12 | — | — | — | — | — | SW 6 | — | SW 6 | SW 6 | — |
— | — | 20 | — | — | — | 3 | 3 | 6 | — | 6 | — | — | — | — | — | 10 | — | 1 | 1 | — | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | SW 12 | SW 12 | — | — | — | — | — | — | — | S 12 | — | — | S 12 | — |
— | — | — | — | — | — | — | 6 | 6 | — | — | — | — | — | — | — | 3 | — | — | 3 | — | |
Wind waves Height (m) Direction Period (s) | SSW 5 | SSW 5 | WNW 4 | W 6 | W 5 | WNW 6 | NW 6 | SW 6 | SW 5 | W 4 | SW 4 | SW 5 | SW 4 | SW 6 | SW 6 | WNW 4 | — | WNW 3 | NW 4 | WNW 3 | W 3 |
70 | 74 | 11 | 152 | 92 | 173 | 124 | 11 | 10 | 10 | 22 | 42 | 43 | 189 | 80 | 10 | — | 1 | 14 | 2 | 1 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 284 | 273 | 88 | 384 | 459 | 548 | 284 | 51 | 275 | 283 | 283 | 251 | 251 | 323 | 187 | 179 | 235 | 235 | 235 | 298 | 246 |
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.











