
Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 25 Jul 2026:
- Best quality surf: Friday 31 Jul, 7PM (local time) - 6.5ft (2.0m), 6s period, SSW swell with offshore winds.
- Most powerful swell: Friday 31 Jul, 7PM (local time) - 6.5ft (2.0m), 6s period, SSW swell with 325 kJ wave energy.
- Next surfable swell (1★+): Friday 31 Jul, 4PM (local time) - 4.5ft (1.4m), 5s period with S swell.
Best Forecast Surf Conditions for Trearddur Bay (Holy Island) this week:
The surf forecast for Trearddur Bay (Holy Island) over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Friday (Jul 31) at 4PM. The primary swell is predicted to be 1.4m and 5s period. The wind is predicted to be offshore as the swell arrives.
The most powerful waves expected at Trearddur Bay (Holy Island) in the next 16 days are 2.0m 6s and forecast to arrive on Friday (Jul 31) at 7PM. Winds are predicted to be offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.1m 5s period and expected on Saturday (Aug 01) at 4AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 4PM (Fri 31st Jul) | 4.5ft (1.4m) 5s |
| Best Surf | 7PM (Fri 31st Jul) | 6.5ft (2.0m) 6s |
| Most Powerful | 7PM (Fri 31st Jul) | 6.5ft (2.0m) 6s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, let’s get this straight. I’ve looked over the charts for Trearddur Bay on Holy Island, and I’ll be honest with you, mate – it’s a grim outlook. We’re looking at a 16-day stretch where there’s barely a ripple worth paddling for.
For the first week, from July 25th right through to the 31st, it’s a total write-off. There’s surf, sure, but it’s tiny, weak, and the wind is almost always on it or cross-onshore, making a mess of things. You’ve got swell heights hanging around 1ft to 4ft, but with short-period windswell and miserable combined energy (most days under 100). It’s a lot of “poor surf conditions” – the kind where you spend more time untangling your leash than riding.
We finally see a glimmer of hope on the afternoon of July 31st. The wind swings offshore from the NE, and the swell bumps up to 5ft from the south with a combined energy of 102 – that’s moderate energy, finally. The period is still a short 5 seconds, so it’s not going to be a thing of beauty, but with clean, offshore wind, it’s the first proper chance to get a wave.
The morning of August 1st is similar: NE offshore wind, 2ft swell from the SW but with a longer 8-second period, giving it a bit more shape for a beach break like this. Combined energy is 67, so it’s still weak. It’s surfable but very ordinary. After that, it drops right off again.
From August 2nd to the 4th, it’s back to flat or near-flat conditions with cross-shore or onshore wind. August 5th is a real tease. The swell punches up to 8ft from the SW on Wednesday morning, with a period of 7 seconds and a combined energy of 595 – strong energy. But the wind is a fresh cross-onshore, turning it into a lumpy, choppy mess. That size with that wind makes it look more interesting for kite surfing than paddle surfing. The afternoon has that swell dropping to 8ft with a 9-second period, and the cross-onshore is gentler, but the wave comment says “gentle cross-onshore and fairly choppy” – it’s not clean.
The rest of the run into the second week, from August 6th to the 9th, is flat and clean but completely undersized – we’re talking 0.3ft to 2ft. Useless.
So, where’s the best? It has to be that window from the afternoon of July 31st through the morning of August 1st. Is it a standout? Not really, because the swell is weak and the period is short, but it’s the only time we get offshore wind and a wave *at all*. Trearddur Bay (Holy Island) is inconsistent and a beginner’s spot, so don’t expect perfection. Crowds are possible here, too.
Water temp? No anomaly is supplied in the data, so it’s just average for the time of year.
Overall, it’s a tough 16 days. Hold tight, forecasts can change.
Rusty.
Short Range ForecastLight rain (total 2mm), mostly falling on Sat night. Very mild (max 18°C on Mon afternoon, min 14°C on Sun night). Mainly fresh winds. | Days 4-6 Weather SummaryMostly dry. Very mild (max 19°C on Tue afternoon, min 14°C on Wed night). Wind will be generally light. | ||||||||||||||||||||
Saturday 25 | Sunday 26 | Monday 27 | Tuesday 28 | Wednesday 29 | Thursday 30 | Friday 31 | |||||||||||||||
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 5 | SW 4 | WNW 5 | WNW 5 | NW 5 | NW 4 | SW 4 | SW 5 | SSW 4 | SSW 4 | SW 4 | SW 3 | SW 2 | SW 3 | SW 4 | SSW 4 | SSW 4 | SSW 4 | S 5 | SSW 7 |
Wave Graph | |||||||||||||||||||||
21 | 35 | 28 | 69 | 69 | 37 | 20 | 19 | 32 | 17 | 15 | 8 | 2 | 1 | 3 | 3 | 2 | 9 | 14 | 102 | 142 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | on | cross-on | cross-on | cross-on | cross | on | cross-on | cross-on | cross-on | cross-on | cross-on | on | on | cross-on | cross | cross | off | off | off | off |
High Tide | 8:27AM4.33m | 8:53PM4.58m | 9:25AM4.48m | 9:42PM4.82m | 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 | |||||||
Low Tide | 2:34PM2.05m | 3:07AM1.98m | 3:25PM1.90m | 3:54AM1.74m | 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 | ||||||||
5:22 | — | — | 5:24 | — | — | 5:26 | — | — | 5:26 | — | — | 5:28 | — | — | 5:30 | — | — | 5:31 | — | — | |
— | — | 9:25 | — | — | 9:23 | — | — | 9:22 | — | — | 9:21 | — | — | 9:19 | — | — | 9:17 | — | — | 9:15 | |
mm | — | — | 2 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 16 | 16 | 17 | 16 | 17 | 17 | 15 | 18 | 18 | 18 | 19 | 18 | 18 | 19 | 18 | 15 | 17 | 17 | 18 | 19 | 18 |
Feels °C | 11 | 14 | 16 | 10 | 11 | 12 | 11 | 15 | 16 | 15 | 15 | 15 | 16 | 17 | 16 | 13 | 15 | 14 | 13 | 14 | 15 |
Swell 1 Height (m) Direction Period (s) | S 12 | NW 4 | S 11 | SW 5 | SW 6 | SW 6 | NW 4 | NW 4 | — | — | — | — | WSW 4 | — | WSW 3 | SW 4 | — | — | — | — | SSW 7 |
3 | 5 | 2 | 23 | 16 | 5 | 20 | 1 | — | — | — | — | 1 | — | 1 | 3 | — | — | — | — | 142 | |
Swell 2 Height (m) Direction Period (s) | — | S 12 | — | — | — | — | — | N 4 | — | — | — | — | — | — | — | — | — | — | — | — | SW 11 |
— | 3 | — | — | — | — | — | 2 | — | — | — | — | — | — | — | — | — | — | — | — | 5 | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | W 4 | SW 5 | SW 4 | WNW 5 | WNW 5 | NW 5 | SW 4 | SW 4 | SW 5 | SSW 4 | SSW 4 | SW 4 | SW 3 | SW 2 | SW 3 | — | SSW 4 | SSW 4 | SSW 4 | S 5 | WNW 4 |
21 | 35 | 28 | 69 | 69 | 37 | 5 | 19 | 32 | 17 | 15 | 8 | 2 | 1 | 3 | — | 2 | 9 | 14 | 102 | 34 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 376 | 376 | 251 | 569 | 548 | 192 | 192 | 251 | 246 | 246 | 246 | 246 | 249 | 249 | 292 | 292 | 292 | 292 | 184 | 0 | 0 |
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.










